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Sample records for ancestral chloroplastic carbonic

  1. Export of carbon from chloroplasts at night

    Energy Technology Data Exchange (ETDEWEB)

    Schleucher, J.; Vanderveer, P.J.; Sharkey, T.D. [Univ. of Wisconsin, Madison, WI (United States)

    1998-12-01

    Hexose export from chloroplasts at night has been inferred in previous studies of mutant and transgenic plants. The authors have tested whether hexose export is the normal route of carbon export from chloroplasts at night. The authors used nuclear magnetic resonance to distinguish glucose (Glc) made from hexose export and Glc made from triose export. Glc synthesized in vitro from fructose-6-phosphate in the presence of deuterium-labeled water had deuterium incorporated at C-2, whereas synthesis from triose phosphates caused C-2 through C-5 to become deuterated. In both tomato (Lycopersicon esculentum L.) and bean (phaseolus vulgaris L.), Glc from sucrose made at night in the presence of deuterium-enriched water was deuterated only in the C-2 position, indicating that >75% of carbon is exported as hexoses at night. In darkness the phosphate in the cytosol was 28 mM, whereas that in the chloroplasts was 5 mW, but hexose phosphates were 10-fold higher in the cytosol than in the chloroplasts. Therefore, hexose phosphates would not move out of chloroplasts without the input of energy. The authors conclude that most carbon leaves chloroplasts at night as Glc, maltose, or higher maltodextrins under normal conditions.

  2. Carbonic anhydrase activity in isolated chloroplasts of chlamydomonas reinhardtii

    International Nuclear Information System (INIS)

    In a new assay of carbonic anhydrase, NaH14CO3 solution at the bottom of a sealed vessel releases 14CO3 which diffuses to the top of the vessel to be assimilated by actively photosynthesizing Chlamydomonas cells. The assay is initiated by illuminating cells and stopped by turning the light off and killing the cells with acid. Enzyme activity was estimated from acid stable radioactivity above the uncatalyzed background level. With bovine carbonic anhydrase, 1.5 Wilbur Anderson Unit (WAU) can be consistantly measured at 5-6 fold above background. Sonicated whole cells of air adapted wild type (+)gave 741.1 ± 12.4 WAU/mg chl. Intact washed cells of mixotrophically grown wall-less mutant CWD(-) and a high CO2 requiring wall-less double mutant CIA-3/CW15 (-) gave 7.1 ± 1.9 and 2.8 ± 7.8 WAU/mg chl respectively. Chloroplasts isolated from CWD and CIA-3/CW15 and subsequently disrupted gave 64.0 ± 14.7 and 2.8 ± 3.2 WAU/mg chl respectively. Chloroplast sonicate from another wall-less mutant CW15(-) gave activity comparable to CWD. Thus on a chlorophyll basis, enzyme activity in chloroplasts from mixotrophically grown cells is about 1/10th of the level found in air adapted wild type cells. CIA-3 seems to lack this activity

  3. Cadmium tolerance of carbon assimilation enzymes and chloroplast in Zn/Cd hyperaccumulator Picris divaricata.

    Science.gov (United States)

    Ying, Rong-Rong; Qiu, Rong-Liang; Tang, Ye-Tao; Hu, Peng-Jie; Qiu, Hao; Chen, Hong-Ru; Shi, Tai-Hong; Morel, Jean-Louis

    2010-01-15

    To better understand the photosynthesis under stress, the effect of cadmium on carbon assimilation and chloroplast ultrastructure of a newly found Zn/Cd hyperaccumulator Picris divaricata in China was investigated in solution culture. The shoot and root Cd concentrations increased with increase in Cd supply, reaching maxima of 1109 and 5604mgkg(-1) dry weight at 75microM Cd, respectively. As Cd supply to P. divaricata increased, the shoot and root dry weight, leaf water content (except 75microM Cd), concentrations of chlorophyll a and b, chlorophyll a/b ratio and the concentration of carotenoids were not depressed at high Cd. However, the stomatal conductance, transpiration rate, net photosynthetic rate and intercellular CO(2) concentration were significantly affected when the Cd concentration reached 10, 10, 25 and 75microM, respectively. Meanwhile, carbonic anhydrase (CA; EC 4.2.1.1) activity and Rubisco (EC 4.1.1.39) content reached maxima in the presence of 50 and 5microM Cd, respectively. In addition, CA activity correlated positively with shoot Cd in plants treated with Cd at a range of 0-50microM. Moreover, the activities of NADP(+)-glyceraldehyde-3-phosphate dehydrogenase (EC 1.2.1.13), Rubisco and fructose-1, 6-bisphosphatase (EC 3.1.3.11) were not significantly suppressed by increased Cd supply. Although the mesophyll cell size was reduced, chloroplast ultrastructure remained intact at the highest Cd treatment. Our finding revealed that P. divaricata chloroplast and the enzymes of carbon assimilation tolerate high levels of Cd, demonstrating its potential in possible application in phytoremediation. PMID:19683362

  4. From extracellular to intracellular: the establishment of mitochondria and chloroplasts.

    Science.gov (United States)

    Whatley, J M; John, P; Whatley, F R

    1979-04-11

    Paracoccus and Rhodopseudomonas are unusual among bacteria in having a majority of the biochemical features of mitochondria; blue-green algae have many of the features of chloroplasts. The theory of serial endosymbiosis proposes that a primitive eukaryote successively took up bacteria and blue-green algae to yield mitochondria and chloroplasts respectively. Possible characteristics of transitional forms are indicated both by the primitive amoeba, Pelomyxa, which lacks mitochondria but contains a permanent population of endosymbiotic bacteria, and by several anomalous eukaryotic algae, e.g. Cyanophora, which contain cyanelles instead of chloroplasts. Blue-green algae appear to be obvious precursors of red algal chloroplasts but the ancestry of other chloroplasts is less certain, though the epizoic symbiont, Prochloron, may resemble the ancestral green algal chloroplast. We speculate that the chloroplasts of the remaining algae may have been a eukaryotic origin. The evolution or organelles from endosymbiotic precursors would involve their integration with the host cell biochemically, structurally and numerically. PMID:36620

  5. Estimating Ancestral Population Parameters

    OpenAIRE

    Wakeley, J.; Hey, J.

    1997-01-01

    The expected numbers of different categories of polymorphic sites are derived for two related models of population history: the isolation model, in which an ancestral population splits into two descendents, and the size-change model, in which a single population undergoes an instantaneous change in size. For the isolation model, the observed numbers of shared, fixed, and exclusive polymorphic sites are used to estimate the relative sizes of the three populations, ancestral plus two descendent...

  6. Ancestral Relationships Using Metafounders

    DEFF Research Database (Denmark)

    Legarra, Andres; Christensen, Ole Fredslund; Vitezica, Zulma G;

    2015-01-01

    Recent use of genomic (marker-based) relationships shows that relationships exist within and across base population (breeds or lines). However, current treatment of pedigree relationships is unable to consider relationships within or across base populations, although such relationships must exist...... due to finite size of the ancestral population and connections between populations. This complicates the conciliation of both approaches and, in particular, combining pedigree with genomic relationships. We present a coherent theoretical framework to consider base population in pedigree relationships....... We suggest a conceptual framework that considers each ancestral population as a finite-sized pool of gametes. This generates across-individual relationships and contrasts with the classical view where each population is considered as an infinite, unrelated pool. Several ancestral populations may be...

  7. Nitrogen control of chloroplast differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, G.W.

    1992-07-01

    This project is directed toward understanding how the availability of nitrogen affects the accumulation of chloroplast pigments and proteins functioning in energy transduction and carbon metabolism. Molecular analyses performed with Chlamydomonas reinhardtii grown in a continuous culture system such that ammonium concentration is maintained at a low steady-state concentration so as to limit cell division. As compared to chloroplasts from cells of non-limiting nitrogen provisions, chloroplasts of N-limited cells are profoundly chlorophyll-deficient but still assimilate carbon for deposition of as starch and as storage lipids. Chlorophyll deficiency arises by limiting accumulation of appropriate nuclear-encoded mRNAs of and by depressed rates of translation of chloroplast mRNAs for apoproteins of reaction centers. Chloroplast translational effects can be partially ascribed to diminished rates of chlorophyll biosynthesis in N-limited cells, but pigment levels are not determinants for expression of the nuclear light-harvesting protein genes. Consequently, other signals that are responsive to nitrogen availability mediate transcriptional or post-transcriptional processes for accumulation of the mRNAs for LHC apoproteins and other mRNAs whose abundance is dependent upon high nitrogen levels. Conversely, limited nitrogen availability promotes accumulation of other proteins involved in carbon metabolism and oxidative electron transport in chloroplasts. Hence, thylakoids of N-limited cells exhibit enhanced chlororespiratory activities wherein oxygen serves as the electron acceptor in a pathway that involves plastoquinone and other electron carrier proteins that remain to be thoroughly characterized. Ongoing and future studies are also outlined.

  8. Update on chloroplast research

    OpenAIRE

    Armbruster, Ute; Pesaresi, Paolo; Pribil, Mathias; Hertle, Alexander; Leister, Dario

    2010-01-01

    Chloroplasts, the green differentiation form of plastids, are the sites of photosynthesis and other important plant functions. Genetic and genomic technologies have greatly boosted the rate of discovery and functional characterization of chloroplast proteins during the past decade. Indeed, data obtained using high-throughput methodologies, in particular proteomics and transcriptomics, are now routinely used to assign functions to chloroplast proteins. Our knowledge of many chloroplast process...

  9. Posttranslational Modifications of Chloroplast Proteins: An Emerging Field.

    Science.gov (United States)

    Lehtimäki, Nina; Koskela, Minna M; Mulo, Paula

    2015-07-01

    Posttranslational modifications of proteins are key effectors of enzyme activity, protein interactions, targeting, and turnover rate, but despite their importance, they are still poorly understood in plants. Although numerous reports have revealed the regulatory role of protein phosphorylation in photosynthesis, various other protein modifications have been identified in chloroplasts only recently. It is known that posttranslational N(α)-acetylation occurs in both nuclear- and plastid-encoded chloroplast proteins, but the physiological significance of this acetylation is not yet understood. Lysine acetylation affects the localization and activity of key metabolic enzymes, and it may work antagonistically or cooperatively with lysine methylation, which also occurs in chloroplasts. In addition, tyrosine nitration may help regulate the repair cycle of photosystem II, while N-glycosylation determines enzyme activity of chloroplastic carbonic anhydrase. This review summarizes the progress in the research field of posttranslational modifications of chloroplast proteins and points out the importance of these modifications in the regulation of chloroplast metabolism. PMID:25911530

  10. Exploring photosynthesis evolution by comparative analysis of metabolic networks between chloroplasts and photosynthetic bacteria

    Directory of Open Access Journals (Sweden)

    Hou Jing

    2006-04-01

    Full Text Available Abstract Background Chloroplasts descended from cyanobacteria and have a drastically reduced genome following an endosymbiotic event. Many genes of the ancestral cyanobacterial genome have been transferred to the plant nuclear genome by horizontal gene transfer. However, a selective set of metabolism pathways is maintained in chloroplasts using both chloroplast genome encoded and nuclear genome encoded enzymes. As an organelle specialized for carrying out photosynthesis, does the chloroplast metabolic network have properties adapted for higher efficiency of photosynthesis? We compared metabolic network properties of chloroplasts and prokaryotic photosynthetic organisms, mostly cyanobacteria, based on metabolic maps derived from genome data to identify features of chloroplast network properties that are different from cyanobacteria and to analyze possible functional significance of those features. Results The properties of the entire metabolic network and the sub-network that consists of reactions directly connected to the Calvin Cycle have been analyzed using hypergraph representation. Results showed that the whole metabolic networks in chloroplast and cyanobacteria both possess small-world network properties. Although the number of compounds and reactions in chloroplasts is less than that in cyanobacteria, the chloroplast's metabolic network has longer average path length, a larger diameter, and is Calvin Cycle -centered, indicating an overall less-dense network structure with specific and local high density areas in chloroplasts. Moreover, chloroplast metabolic network exhibits a better modular organization than cyanobacterial ones. Enzymes involved in the same metabolic processes tend to cluster into the same module in chloroplasts. Conclusion In summary, the differences in metabolic network properties may reflect the evolutionary changes during endosymbiosis that led to the improvement of the photosynthesis efficiency in higher plants. Our

  11. Nitrogen control of chloroplast development: Progress report

    International Nuclear Information System (INIS)

    A manifestation of nitrogen deficiency in vascular plants and algae is chlorosis, indicating that chloroplast biogenesis can be strongly restricted by direct or indirect effects of nitrogen assimilation products. To define the molecular basis of nitrogen responses we are using Chlamydomonas reinhardtii. Depending on the levels of ammonium, steady-state deficiency conditions are established such that the cellular levels of chlorophylls and xanthophylls are depressed. Chloroplasts in nitrogen-deficient cells contain appreciable levels of carbon assimilation enzyme and thylakoids with high electron transport activities. However, the light harvesting complexes are nearly absent and Photosystem I exhibits unusual characteristics. Studies of rates of protein synthesis by in vivo pulse-chase labeling and levels of RNAs encoded by the chloroplast and nuclear genomes have been initiated: the accumulation of transcripts for the nuclear light-harvesting apoproteins is dramatically altered qualitatively and quantitatively; there is no major effect on chloroplast RNAs but, in general, these are inefficiently utilized for protein synthesis until nitrogen is provided to the cultures. Supplying nitrogen results in an almost immediate release of chloroplast mRNAs from a translational arrest but the stimulation of the accumulation of nuclear transcripts for light-harvesting apoproteins does not occur until after a 1-2 hour lag

  12. Ancestral reconstruction of tick lineages.

    Science.gov (United States)

    Mans, Ben J; de Castro, Minique H; Pienaar, Ronel; de Klerk, Daniel; Gaven, Philasande; Genu, Siyamcela; Latif, Abdalla A

    2016-06-01

    Ancestral reconstruction in its fullest sense aims to describe the complete evolutionary history of a lineage. This depends on accurate phylogenies and an understanding of the key characters of each parental lineage. An attempt is made to delineate our current knowledge with regard to the ancestral reconstruction of the tick (Ixodida) lineage. Tick characters may be assigned to Core of Life, Lineages of Life or Edges of Life phenomena depending on how far back these characters may be assigned in the evolutionary Tree of Life. These include housekeeping genes, sub-cellular systems, heme processing (Core of Life), development, moulting, appendages, nervous and organ systems, homeostasis, respiration (Lineages of Life), specific adaptations to a blood-feeding lifestyle, including the complexities of salivary gland secretions and tick-host interactions (Edges of Life). The phylogenetic relationships of lineages, their origins and importance in ancestral reconstruction are discussed. Uncertainties with respect to systematic relationships, ancestral reconstruction and the challenges faced in comparative transcriptomics (next-generation sequencing approaches) are highlighted. While almost 150 years of information regarding tick biology have been assembled, progress in recent years indicates that we are in the infancy of understanding tick evolution. Even so, broad reconstructions can be made with relation to biological features associated with various lineages. Conservation of characters shared with sister and parent lineages are evident, but appreciable differences are present in the tick lineage indicating modification with descent, as expected for Darwinian evolutionary theory. Many of these differences can be related to the hematophagous lifestyle of ticks. PMID:26868413

  13. Blocking the Metabolism of Starch Breakdown Products in Arabidopsis Leaves Triggers Chloroplast Degradation

    OpenAIRE

    Stettler, Michaela; Eicke, Simona; Mettler, Tabea; Messerli, Gaëlle; Hörtensteiner, Stefan; Zeeman, Samuel C.

    2009-01-01

    In most plants, a large fraction of photo-assimilated carbon is stored in the chloroplasts during the day as starch and remobilized during the subsequent night to support metabolism. Mutations blocking either starch synthesis or starch breakdown in Arabidopsis thaliana reduce plant growth. Maltose is the major product of starch breakdown exported from the chloroplast at night. The maltose excess 1 mutant (mex1), which lacks the chloroplast envelope maltose transporter, accumulates high levels...

  14. Shrinkage Effect in Ancestral Maximum Likelihood

    CERN Document Server

    Mossel, Elchanan; Steel, Mike

    2008-01-01

    Ancestral maximum likelihood (AML) is a method that simultaneously reconstructs a phylogenetic tree and ancestral sequences from extant data (sequences at the leaves). The tree and ancestral sequences maximize the probability of observing the given data under a Markov model of sequence evolution, in which branch lengths are also optimized but constrained to take the same value on any edge across all sequence sites. AML differs from the more usual form of maximum likelihood (ML) in phylogenetics because ML averages over all possible ancestral sequences. ML has long been known to be statistically consistent -- that is, it converges on the correct tree with probability approaching 1 as the sequence length grows. However, the statistical consistency of AML has not been formally determined, despite informal remarks in a literature that dates back 20 years. In this short note we prove a general result that implies that AML is statistically inconsistent. In particular we show that AML can `shrink' short edges in a t...

  15. Genetic Analysis of Chloroplast Translation

    Energy Technology Data Exchange (ETDEWEB)

    Barkan, Alice

    2005-08-15

    The assembly of the photosynthetic apparatus requires the concerted action of hundreds of genes distributed between the two physically separate genomes in the nucleus and chloroplast. Nuclear genes coordinate this process by controlling the expression of chloroplast genes in response to developmental and environmental cues. However, few regulatory factors have been identified. We used mutant phenotypes to identify nuclear genes in maize that modulate chloroplast translation, a key control point in chloroplast gene expression. This project focused on the nuclear gene crp1, required for the translation of two chloroplast mRNAs. CRP1 is related to fungal proteins involved in the translation of mitochondrial mRNAs, and is the founding member of a large gene family in plants, with {approx}450 members. Members of the CRP1 family are defined by a repeated 35 amino acid motif called a ''PPR'' motif. The PPR motif is closely related to the TPR motif, which mediates protein-protein interactions. We and others have speculated that PPR tracts adopt a structure similar to that of TPR tracts, but with a substrate binding surface adapted to bind RNA instead of protein. To understand how CRP1 influences the translation of specific chloroplast mRNAs, we sought proteins that interact with CRP1, and identified the RNAs associated with CRP1 in vivo. We showed that CRP1 is associated in vivo with the mRNAs whose translation it activates. To explore the functions of PPR proteins more generally, we sought mutations in other PPR-encoding genes: mutations in the maize PPR2 and PPR4 were shown to disrupt chloroplast ribosome biogenesis and chloroplast trans-splicing, respectively. These and other results suggest that the nuclear-encoded PPR family plays a major role in modulating the expression of the chloroplast genome in higher plants.

  16. Noncoding RNA mediated traffic of foreign mRNA into chloroplasts reveals a novel signaling mechanism in plants.

    Directory of Open Access Journals (Sweden)

    Gustavo Gómez

    Full Text Available Communication between chloroplasts and the nucleus is one of the milestones of the evolution of plants on earth. Proteins encoded by ancestral chloroplast-endogenous genes were transferred to the nucleus during the endosymbiotic evolution and originated this communication, which is mainly dependent on specific transit-peptides. However, the identification of nuclear-encoded proteins targeted to the chloroplast lacking these canonical signals suggests the existence of an alternative cellular pathway tuning this metabolic crosstalk. Non-coding RNAS (NcRNAs are increasingly recognized as regulators of gene expression as they play roles previously believed to correspond to proteins. Avsunviroidae family viroids are the only noncoding functional RNAs that have been reported to traffic inside the chloroplasts. Elucidating mechanisms used by these pathogens to enter this organelle will unearth novel transport pathways in plant cells. Here we show that a viroid-derived NcRNA acting as a 5'UTR-end mediates the functional import of Green Fluorescent Protein (GFP mRNA into chloroplast. This claim is supported by the observation at confocal microscopy of a selective accumulation of GFP in the chloroplast of the leaves expressing the chimeric vd-5'UTR/GFP and by the detection of the GFP mRNA in chloroplasts isolated from cells expressing this construct. These results support the existence of an alternative signaling mechanism in plants between the host cell and chloroplasts, where an ncRNA functions as a key regulatory molecule to control the accumulation of nuclear-encoded proteins in this organelle. In addition, our findings provide a conceptual framework to develop new biotechnological tools in systems using plant chloroplast as bioreactors. Finally, viroids of the family Avsunviroidae have probably evolved to subvert this signaling mechanism to regulate their differential traffic into the chloroplast of infected cells.

  17. Nitrogen control of chloroplast differentiation. Annual progress report

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, G.W.

    1992-07-01

    This project is directed toward understanding how the availability of nitrogen affects the accumulation of chloroplast pigments and proteins functioning in energy transduction and carbon metabolism. Molecular analyses performed with Chlamydomonas reinhardtii grown in a continuous culture system such that ammonium concentration is maintained at a low steady-state concentration so as to limit cell division. As compared to chloroplasts from cells of non-limiting nitrogen provisions, chloroplasts of N-limited cells are profoundly chlorophyll-deficient but still assimilate carbon for deposition of as starch and as storage lipids. Chlorophyll deficiency arises by limiting accumulation of appropriate nuclear-encoded mRNAs of and by depressed rates of translation of chloroplast mRNAs for apoproteins of reaction centers. Chloroplast translational effects can be partially ascribed to diminished rates of chlorophyll biosynthesis in N-limited cells, but pigment levels are not determinants for expression of the nuclear light-harvesting protein genes. Consequently, other signals that are responsive to nitrogen availability mediate transcriptional or post-transcriptional processes for accumulation of the mRNAs for LHC apoproteins and other mRNAs whose abundance is dependent upon high nitrogen levels. Conversely, limited nitrogen availability promotes accumulation of other proteins involved in carbon metabolism and oxidative electron transport in chloroplasts. Hence, thylakoids of N-limited cells exhibit enhanced chlororespiratory activities wherein oxygen serves as the electron acceptor in a pathway that involves plastoquinone and other electron carrier proteins that remain to be thoroughly characterized. Ongoing and future studies are also outlined.

  18. Chloroplast phosphoproteins: distribution of phosphoproteins within spinach chloroplasts

    International Nuclear Information System (INIS)

    The distribution of phosphoproteins within spinach chloroplasts was studied. Intact chloroplasts with good rates of CO2-dependent oxygen evolution were fed (γ-32P)ATP and then separated into stroma and membrane fractions. Only one major labelled stroma protein was identified by gel electrophoresis/autoradiography, with a mol. wt. of 66000. The membranes were separated into envelopes and thylakoid fractions. Three labelled proteins were separated by gel electrophoresis in the envelope with mol. wt. of 50500, 29000 and 13000. (author)

  19. Chloroplast ribosomes and protein synthesis.

    OpenAIRE

    Harris, E. H.; Boynton, J E; Gillham, N W

    1994-01-01

    Consistent with their postulated origin from endosymbiotic cyanobacteria, chloroplasts of plants and algae have ribosomes whose component RNAs and proteins are strikingly similar to those of eubacteria. Comparison of the secondary structures of 16S rRNAs of chloroplasts and bacteria has been particularly useful in identifying highly conserved regions likely to have essential functions. Comparative analysis of ribosomal protein sequences may likewise prove valuable in determining their roles i...

  20. Extending the biosynthetic repertoires of cyanobacteria and chloroplasts

    DEFF Research Database (Denmark)

    Nielsen, Agnieszka Janina Zygadlo; Mellor, Silas Busck; Vavitsas, Konstantinos;

    2016-01-01

    The chloroplasts found in plants and algae, and photosynthetic microorganisms such as cyanobacteria, are emerging hosts for sustainable production of valuable biochemicals, using only inorganic nutrients, water, CO2 and light as inputs. In the past decade, many bioengineering efforts have focused...... on metabolic engineering and synthetic biology in the chloroplast or in cyanobacteria for the production of fuels, chemicals, as well as complex, high-value bioactive molecules. Biosynthesis of all these compounds can be performed in photosynthetic organelles/organisms by heterologous expression...... of chloroplasts and cyanobacteria as biosynthetic compartments and hosts, and we estimate the production levels to be expected from photosynthetic hosts in light of the fraction of electrons and carbon that can potentially be diverted from photosynthesis. The supply of reducing power, in the form of electrons...

  1. Extending the biosynthetic repertoires of cyanobacteria and chloroplasts.

    Science.gov (United States)

    Nielsen, Agnieszka Zygadlo; Mellor, Silas Busck; Vavitsas, Konstantinos; Wlodarczyk, Artur Jacek; Gnanasekaran, Thiyagarajan; Perestrello Ramos H de Jesus, Maria; King, Brian Christopher; Bakowski, Kamil; Jensen, Poul Erik

    2016-07-01

    Chloroplasts in plants and algae and photosynthetic microorganisms such as cyanobacteria are emerging hosts for sustainable production of valuable biochemicals, using only inorganic nutrients, water, CO2 and light as inputs. In the past decade, many bioengineering efforts have focused on metabolic engineering and synthetic biology in the chloroplast or in cyanobacteria for the production of fuels, chemicals and complex, high-value bioactive molecules. Biosynthesis of all these compounds can be performed in photosynthetic organelles/organisms by heterologous expression of the appropriate pathways, but this requires optimization of carbon flux and reducing power, and a thorough understanding of regulatory pathways. Secretion or storage of the compounds produced can be exploited for the isolation or confinement of the desired compounds. In this review, we explore the use of chloroplasts and cyanobacteria as biosynthetic compartments and hosts, and we estimate the levels of production to be expected from photosynthetic hosts in light of the fraction of electrons and carbon that can potentially be diverted from photosynthesis. The supply of reducing power, in the form of electrons derived from the photosynthetic light reactions, appears to be non-limiting, but redirection of the fixed carbon via precursor molecules presents a challenge. We also discuss the available synthetic biology tools and the need to expand the molecular toolbox to facilitate cellular reprogramming for increased production yields in both cyanobacteria and chloroplasts. PMID:27005523

  2. Algorithms of Ancestral Gene Length Reconstruction

    Directory of Open Access Journals (Sweden)

    Alexander Bolshoy

    2013-01-01

    Full Text Available Ancestral sequence reconstruction is a well-known problem in molecular evolution. The problem presented in this study is inspired by sequence reconstruction, but instead of leaf-associated sequences we consider only their lengths. We call this problem ancestral gene length reconstruction. It is a problem of finding an optimal labeling which minimizes the total length’s sum of the edges, where both a tree and nonnegative integers associated with corresponding leaves of the tree are the input. In this paper we give a linear algorithm to solve the problem on binary trees for the Manhattan cost function .

  3. Isolation of chloroplastic phosphoglycerate kinase

    Energy Technology Data Exchange (ETDEWEB)

    Macioszek, J.; Anderson, L.E. (Univ. of Illinois, Chicago (USA)); Anderson, J.B. (Pennsylvania State Univ., University Park (USA))

    1990-09-01

    We report here a method for the isolation of high specific activity phosphoglycerate kinase (EC 2.7.2.3) from chloroplasts. The enzyme has been purified over 200-fold from pea (Pisum sativum L.) stromal extracts to apparent homogeneity with 23% recovery. Negative cooperativity is observed with the two enzyme phosphoglycerate kinase/glyceraldehyde-3-P dehydrogenase (EC 1.2.1.13) couple restored from the purified enzymes when NADPH is the reducing pyridine nucleotide, consistent with earlier results obtained with crude chloroplastic extracts. Michaelis Menten kinetics are observed when 3-phosphoglycerate is held constant and phosphoglycerate kinase is varied, which suggests that phosphoglycerate kinase-bound 1,3-bisphosphoglycerate may be the preferred substrate for glyceraldehyde-3-P dehydrogenase in the chloroplast.

  4. Biosynthesis of starch in chloroplasts.

    Science.gov (United States)

    Nomura, T; Nakayama, N; Murata, T; Akazawa, T

    1967-03-01

    The enzymic synthesis of ADP-glucose and UDP-glucose by chloroplastic pyrophosphorylase of bean and rice leaves has been demonstrated by paper chromatographic techniques. In both tissues, the activity of UDP-glucose-pyrophosphorylase was much higher than ADP-glucose-pyrophosphorylase. Glycerate-3-phosphate, phosphoenolpyruvate and fructose-1,6-diphosphate did not stimulate ADP-glucose formation by a pyrophosphorylation reaction. The major metabolic pathway for UDP-glucose utilization appears to be the synthesis of either sucrose or sucrose-P. On the other hand, a specific precursor role of ADP-glucose for synthesizing chloroplast starch by the ADP-glucose-starch transglucosylase reaction is supported by the coupled enzyme system of ADP-glucose-pyrophosphorylase and transglucosylase, isolated from chloroplasts. None of the glycolytic intermediates stimulated the glucose transfer in the enzyme sequence of reaction system employed. PMID:4292567

  5. Functional chloroplasts in metazoan cells - a unique evolutionary strategy in animal life

    Directory of Open Access Journals (Sweden)

    Krug Patrick J

    2009-12-01

    Full Text Available Abstract Background Among metazoans, retention of functional diet-derived chloroplasts (kleptoplasty is known only from the sea slug taxon Sacoglossa (Gastropoda: Opisthobranchia. Intracellular maintenance of plastids in the slug's digestive epithelium has long attracted interest given its implications for understanding the evolution of endosymbiosis. However, photosynthetic ability varies widely among sacoglossans; some species have no plastid retention while others survive for months solely on photosynthesis. We present a molecular phylogenetic hypothesis for the Sacoglossa and a survey of kleptoplasty from representatives of all major clades. We sought to quantify variation in photosynthetic ability among lineages, identify phylogenetic origins of plastid retention, and assess whether kleptoplasty was a key character in the radiation of the Sacoglossa. Results Three levels of photosynthetic activity were detected: (1 no functional retention; (2 short-term retention lasting about one week; and (3 long-term retention for over a month. Phylogenetic analysis of one nuclear and two mitochondrial loci revealed reciprocal monophyly of the shelled Oxynoacea and shell-less Plakobranchacea, the latter comprising a monophyletic Plakobranchoidea and paraphyletic Limapontioidea. Only species in the Plakobranchoidea expressed short- or long-term kleptoplasty, most belonging to a speciose clade of slugs bearing parapodia (lateral flaps covering the dorsum. Bayesian ancestral character state reconstructions indicated that functional short-term retention arose once in the last common ancestor of Plakobranchoidea, and independently evolved into long-term retention in four derived species. Conclusion We propose a sequential progression from short- to long-term kleptoplasty, with different adaptations involved in each step. Short-term kleptoplasty likely arose as a deficiency in plastid digestion, yielding additional energy via the release of fixed carbon

  6. Molecular and biochemical analyses of transgenic nicotiana tabacum plants metabolizing glycolate in the chloroplasts

    OpenAIRE

    Thiruveedhi, Krishnaveni

    2006-01-01

    The photorespiratory pathway in C3 plants consumes not only ATP and reducing equivalents but also results in loss of ~ 25% carbon that has been fixed during the process of photosynthesis. In the present study, an alternative biochemical pathway for the metabolism of glycolate was established in the chloroplasts of tobacco (Nicotiana tabacum) plants. The new pathway aims at increasing the refixation of CO2 inside the chloroplasts and thereby at suppressing photorespiration in C3 plants. The pa...

  7. Free radical generation and antioxidant content in chloroplasts from soybean leaves expsoed to ultraviolet-B

    Energy Technology Data Exchange (ETDEWEB)

    Galatro, A.; Simontacchi, M.; Puntarulo, S. [Univ. of Buenos Aires, School of Pharmacy and Biochemistry, Physical Chemistry, Buenos Aires (Argentina)

    2001-07-01

    The aim of this work was to study the effect of ultraviolet-B (UV-B) exposure on oxidative status in chloroplasts isolated from soybean (Glycine max cv. Hood). Chloroplasts were isolated from soybean leaves excised from either control seedlings or those exposed to 30 and 60 kJ m{sup -2} day{sup -1} of UV-B radiation for 4 days. Chloroplastic oxidative conditions were assessed as carbon-centered radical, carbonyl groups and ascorbyl radical content. Treatment with UV-B increased the carbon-centered radical-dependent EPR signal significantly by 55 and 100% in chloroplasts from leaves exposed to 30 and 60 kJ m{sup -2} day{sup -1} UV-B, respectively, compared to radical content in chloroplasts from control leaves. The content of carbonyl groups increased by 37 and 62% in chloroplasts isolated from soybean leaves irradiated for 4 days with 30 and 60 kJ m{sup -2} day{sup -1} UV-B, respectively. The content of soluble metabolites in isolated chloroplasts should not be taken as absolute in vivo values; however, these data are valuable for comparative studies. UV-B exposure did not significantly affect ascorbyl radical content compared to controls. The content of ascorbic acid and thiols in chloroplasts isolated from leaves exposed to 60 kJ m{sup -2} day{sup -1} UV-B was increased by 117 and 20.8%, respectively, compared to controls. Neither the content of total carotene nor that of {beta}-carotene or {alpha}-tocopherol was affected by the irradiation. The results: presented here suggest that the increased content of lipid radicals and oxidized proteins in the chloroplasts isolated from leaves exposed to UV-B could be ascribed to both the lack of antioxidant response in the lipid soluble fraction and the modest increase in the soluble antioxidant content. (au)

  8. Programmed chloroplast destruction during leaf senescence involves 13-lipoxygenase (13-LOX).

    Science.gov (United States)

    Springer, Armin; Kang, ChulHee; Rustgi, Sachin; von Wettstein, Diter; Reinbothe, Christiane; Pollmann, Stephan; Reinbothe, Steffen

    2016-03-22

    Leaf senescence is the terminal stage in the development of perennial plants. Massive physiological changes occur that lead to the shut down of photosynthesis and a cessation of growth. Leaf senescence involves the selective destruction of the chloroplast as the site of photosynthesis. Here, we show that 13-lipoxygenase (13-LOX) accomplishes a key role in the destruction of chloroplasts in senescing plants and propose a critical role of its NH2-terminal chloroplast transit peptide. The 13-LOX enzyme identified here accumulated in the plastid envelope and catalyzed the dioxygenation of unsaturated membrane fatty acids, leading to a selective destruction of the chloroplast and the release of stromal constituents. Because 13-LOX pathway products comprise compounds involved in insect deterrence and pathogen defense (volatile aldehydes and oxylipins), a mechanism of unmolested nitrogen and carbon relocation is suggested that occurs from leaves to seeds and roots during fall. PMID:26969728

  9. Formation of putative chloroplast cytochromes in isolated developing pea chloroplasts

    International Nuclear Information System (INIS)

    In addition to chlorophyll-protein complexes, other proteins were labeled when isolated developing pea chloroplasts were incubated with [14C]-5-aminolevulinic acid [14C]-ALA. The major labeled band (M/sub r/ = 43 kDa by LDS-PAGE) was labeled even in the presence of chloramphenicol. Heme-dependent peroxidase activity (as detected by the tetramethyl benzidine-H2O2 stain) was not visibly associated with this band. The radioactive band was stable to heat, 5% HCl in acetone, and was absent if the incubation with [14C]-5-aminolevulinic acid was carried out in the presence of N-methyl protoporphyrin IX dimethyl ester (a specific inhibitor of ferrochelatase). Organic solvent extraction procedures for the enrichment of cytochrome f from chloroplast membranes also extracted this unknown labeled product. It was concluded that this labeled product was probably a c-type cytochrome. The effect of exogenous iron, iron chelators, gabaculine (an inhibitor of ALA synthesis) and other incubation conditions upon the in vitro formation of putative chloroplast cytochromes will be discussed

  10. Protein methylation in pea chloroplasts

    International Nuclear Information System (INIS)

    The methylation of chloroplast proteins has been investigated by incubating intact pea (Pisum sativum) chloroplasts with [3H-methyl]-S-adenosylmethionine. Incubation in the light increases the amount of methylation in both the thylakoid and stromal fractions. Numerous thylakoid proteins serve as substrates for the methyltransfer reactions. Three of these thylakoid proteins are methylated to a significantly greater extent in the light than in the dark. The primary stromal polypeptide methylated is the large subunit of ribulose bisphosphate carboxylase/oxygenase. One other stromal polypeptide is also methylated much more in the light than in the dark. Two distinct types of protein methylation occur. One methylinkage is stable to basic conditions whereas a second type is base labile. The base-stable linkage is indicative of N-methylation of amino acid residues while base-lability is suggestive of carboxymethylation of amino acid residues. Labeling in the light increases the percentage of methylation that is base labile in the thylakoid fraction while no difference is observed in the amount of base-labile methylations in light-labeled and dark-labeled stromal proteins. Also suggestive of carboxymethylation is the detection of volatile [3H]methyl radioactivity which increases during the labeling period and is greater in chloroplasts labeled in the light as opposed to being labeled in the dark; this implies in vivo turnover of the [3H]methyl group

  11. On the structure of the spinach chloroplast

    NARCIS (Netherlands)

    Thomas, J.B.; Bustraan, M.; Paris, C.H.

    1952-01-01

    The structure of spinach chloroplasts was investigated with the aid of the electron microscope. It has been established that: 1. 1. the outer membrane of the chloroplasts is composed of both proteins and lipoids. 2. 2. the stroma is also built up by these components. 3. 3. within the stroma memb

  12. Reconstruction of ancestral protein sequences and its applications

    Directory of Open Access Journals (Sweden)

    Grishin Nick V

    2004-09-01

    Full Text Available Abstract Background Modern-day proteins were selected during long evolutionary history as descendants of ancient life forms. In silico reconstruction of such ancestral protein sequences facilitates our understanding of evolutionary processes, protein classification and biological function. Additionally, reconstructed ancestral protein sequences could serve to fill in sequence space thus aiding remote homology inference. Results We developed ANCESCON, a package for distance-based phylogenetic inference and reconstruction of ancestral protein sequences that takes into account the observed variation of evolutionary rates between positions that more precisely describes the evolution of protein families. To improve the accuracy of evolutionary distance estimation and ancestral sequence reconstruction, two approaches are proposed to estimate position-specific evolutionary rates. Comparisons show that at large evolutionary distances our method gives more accurate ancestral sequence reconstruction than PAML, PHYLIP and PAUP*. We apply the reconstructed ancestral sequences to homology inference and functional site prediction. We show that the usage of hypothetical ancestors together with the present day sequences improves profile-based sequence similarity searches; and that ancestral sequence reconstruction methods can be used to predict positions with functional specificity. Conclusions As a computational tool to reconstruct ancestral protein sequences from a given multiple sequence alignment, ANCESCON shows high accuracy in tests and helps detection of remote homologs and prediction of functional sites. ANCESCON is freely available for non-commercial use. Pre-compiled versions for several platforms can be downloaded from ftp://iole.swmed.edu/pub/ANCESCON/.

  13. Chloroplasts as functional organelles in animal tissues.

    Science.gov (United States)

    Trench, R K; Greene, R W; Bystrom, B G

    1969-08-01

    The marine gastropod molluscs Tridachia crispata, Tridachiella diomedea, and Placobranchus ianthobapsus (Sacoglossa, Opisthobranchia) possess free functional chloroplasts within the cells of the digestive diverticula, as determined by observations on ultrastructure, pigment analyses, and experiments on photosynthetic capacity. In the light, the chloroplasts incorporate H(14)CO(3) (-)in situ. Reduced radiocarbon is translocated to various chloroplast-free tissues in the animals. The slugs feed on siphonaceous algae from which the chloroplasts are derived. Pigments from the slugs and from known siphonaceous algae, when separated chromatographically and compared, showed similar components. Absorption spectra of extracts of slugs and algae were very similar. The larvae of the slugs are pigment-free up to the post-veliger stage, suggesting that chloroplasts are acquired de novo. with each new generation. PMID:5792329

  14. Posttranslational modifications of FERREDOXIN-NADP+ OXIDOREDUCTASE in Arabidopsis chloroplasts.

    Science.gov (United States)

    Lehtimäki, Nina; Koskela, Minna M; Dahlström, Käthe M; Pakula, Eveliina; Lintala, Minna; Scholz, Martin; Hippler, Michael; Hanke, Guy T; Rokka, Anne; Battchikova, Natalia; Salminen, Tiina A; Mulo, Paula

    2014-12-01

    Rapid responses of chloroplast metabolism and adjustments to photosynthetic machinery are of utmost importance for plants' survival in a fluctuating environment. These changes may be achieved through posttranslational modifications of proteins, which are known to affect the activity, interactions, and localization of proteins. Recent studies have accumulated evidence about the crucial role of a multitude of modifications, including acetylation, methylation, and glycosylation, in the regulation of chloroplast proteins. Both of the Arabidopsis (Arabidopsis thaliana) leaf-type FERREDOXIN-NADP(+) OXIDOREDUCTASE (FNR) isoforms, the key enzymes linking the light reactions of photosynthesis to carbon assimilation, exist as two distinct forms with different isoelectric points. We show that both AtFNR isoforms contain multiple alternative amino termini and undergo light-responsive addition of an acetyl group to the α-amino group of the amino-terminal amino acid of proteins, which causes the change in isoelectric point. Both isoforms were also found to contain acetylation of a conserved lysine residue near the active site, while no evidence for in vivo phosphorylation or glycosylation was detected. The dynamic, multilayer regulation of AtFNR exemplifies the complex regulatory network systems controlling chloroplast proteins by a range of posttranslational modifications, which continues to emerge as a novel area within photosynthesis research. PMID:25301888

  15. Dual Protein Localization to the Envelope and Thylakoid Membranes Within the Chloroplast.

    Science.gov (United States)

    Klasek, Laura; Inoue, Kentaro

    2016-01-01

    The chloroplast houses various metabolic processes essential for plant viability. This organelle originated from an ancestral cyanobacterium via endosymbiosis and maintains the three membranes of its progenitor. Among them, the outer envelope membrane functions mainly in communication with cytoplasmic components while the inner envelope membrane houses selective transport of various metabolites and the biosynthesis of several compounds, including membrane lipids. These two envelope membranes also play essential roles in import of nuclear-encoded proteins and in organelle division. The third membrane, the internal membrane system known as the thylakoid, houses photosynthetic electron transport and chemiosmotic phosphorylation. The inner envelope and thylakoid membranes share similar lipid composition. Specific targeting pathways determine their defined proteomes and, thus, their distinct functions. Nonetheless, several proteins have been shown to exist in both the envelope and thylakoid membranes. These proteins include those that play roles in protein transport, tetrapyrrole biosynthesis, membrane dynamics, or transport of nucleotides or inorganic phosphate. In this review, we summarize the current knowledge about proteins localized to both the envelope and thylakoid membranes in the chloroplast, discussing their roles in each membrane and potential mechanisms of their dual localization. Addressing the unanswered questions about these dual-localized proteins should help advance our understanding of chloroplast development, protein transport, and metabolic regulation. PMID:26944623

  16. Chloroplast protein targeting involves localized translation in Chlamydomonas

    OpenAIRE

    Uniacke, James; Zerges, William

    2009-01-01

    The compartmentalization of eukaryotic cells requires that newly synthesized proteins be targeted to the compartments in which they function. In chloroplasts, a few thousand proteins function in photosynthesis, expression of the chloroplast genome, and other processes. Most chloroplast proteins are synthesized in the cytoplasm, imported, and then targeted to a specific chloroplast compartment. The remainder are encoded by the chloroplast genome, synthesized within the organelle, and targeted ...

  17. The structure of cell chloroplasts of spring cereals

    OpenAIRE

    Vladislav V. Zhuk; Mykola M. Musyenko

    2012-01-01

    It is shown that in wheat chloroplasts thylakoids are localized on the periphery and in the central part are strong starch grains. In the chloroplasts of barley found small stack of thylakoids. Unlike wheat, the number of starch grains in chloroplasts of barley is more, but they are smaller. Oat chloroplasts were significantly smaller than the other studied cereals. Thus, cell chloroplasts of leaves of wheat, barley and oats differed significantly in size and structure, but had have clearly o...

  18. The complexity of chloroplast chaperonins.

    Science.gov (United States)

    Vitlin Gruber, Anna; Nisemblat, Shahar; Azem, Abdussalam; Weiss, Celeste

    2013-12-01

    Type I chaperonins are large oligomeric protein ensembles that are involved in the folding and assembly of other proteins. Chloroplast chaperonins and co-chaperonins exist in multiple copies of two distinct isoforms that can combine to form a range of labile oligomeric structures. This complex system increases the potential number of chaperonin substrates and possibilities for regulation. The incorporation of unique subunits into the oligomer can modify substrate specificity. Some subunits are upregulated in response to heat shock and some show organ-specific expression, whereas others possess additional functions that are unrelated to their role in protein folding. Accumulating evidence suggests that specific subunits have distinct roles in biogenesis of ribulose-1,5-bisphosphate carboxylase oxygenase (Rubisco). PMID:24035661

  19. CURE-Chloroplast: A chloroplast C-to-U RNA editing predictor for seed plants

    Directory of Open Access Journals (Sweden)

    Li Yanda

    2009-05-01

    Full Text Available Abstract Background RNA editing is a type of post-transcriptional modification of RNA and belongs to the class of mechanisms that contribute to the complexity of transcriptomes. C-to-U RNA editing is commonly observed in plant mitochondria and chloroplasts. The in vivo mechanism of recognizing C-to-U RNA editing sites is still unknown. In recent years, many efforts have been made to computationally predict C-to-U RNA editing sites in the mitochondria of seed plants, but there is still no algorithm available for C-to-U RNA editing site prediction in the chloroplasts of seed plants. Results In this paper, we extend our algorithm CURE, which can accurately predict the C-to-U RNA editing sites in mitochondria, to predict C-to-U RNA editing sites in the chloroplasts of seed plants. The algorithm achieves over 80% sensitivity and over 99% specificity. We implement the algorithm as an online service called CURE-Chloroplast http://bioinfo.au.tsinghua.edu.cn/pure. Conclusion CURE-Chloroplast is an online service for predicting the C-to-U RNA editing sites in the chloroplasts of seed plants. The online service allows the processing of entire chloroplast genome sequences. Since CURE-Chloroplast performs very well, it could be a helpful tool in the study of C-to-U RNA editing in the chloroplasts of seed plants.

  20. Solar energy conversion by chloroplast photoelectrochemical cells

    Science.gov (United States)

    Bhardwaj, R.; Pan, R. L.; Gross, E. L.

    1981-01-01

    A photoelectrochemical cell based on chloroplasts which generates large photovoltages and photocurrents from solar energy is presented. The cell contains broken Type C chloroplasts placed on a filter separating compartments containing an electron acceptor and electron donor with platinum electrodes in each. Photovoltages were observed across a load resistance of 3000 ohms with either flavin mononucleotide or anthroquinone 2-sulphonate as the electron acceptor and dichlorophenol indophenol as the donor, and persisted for 1-2 hr after the light was turned off. The powers and short circuit currents obtained in the chloroplast cells are nearly equal to those obtained in cells based on isolated photosystem I particles. Finally, an efficiency of 2.3% has been measured for the chloroplast contribution to the total power in flavin mononucleotide cells.

  1. Chloroplasts in tissues of some herbaceous stems

    Directory of Open Access Journals (Sweden)

    Roman Maksymowych

    2014-02-01

    Full Text Available Serial sections of mature stems of ten species of herbaceous dicotyledonous plants were examined by light microscopy and the number of chloroplasts per cell was estimated in epidermis, collenchyma and cortex. Chloroplast identification was made by both light and transmission electron microscopy. Chloroplasts were present in epidermis, collenchyma and cortex tissues of all stems examined. The smallest number of chloroplasts was observed in the epidermis. Collenchyma cells had the largest number of plastids in four of the genera and cortex cells had the largest number in the remaining six genera. The stem epidermis of all genera contained stomates as demonstrated by scanning electron microscopy and aceto-orcein stained epidermal peels.

  2. A comparison of rice chloroplast genomes

    DEFF Research Database (Denmark)

    Tang, Jiabin; Xia, Hong'ai; Cao, Mengliang; Zhang, Xiuqing; Zeng, Wanyong; Hu, Songnian; Tong, Wei; Wang, Jun; Wang, Jian; Yu, Jun; Yang, Huanming; Zhu, Lihuang

    2004-01-01

    ), which are both parental varieties of the super-hybrid rice, LYP9. Based on the patterns of high sequence coverage, we partitioned chloroplast sequence variations into two classes, intravarietal and intersubspecific polymorphisms. Intravarietal polymorphisms refer to variations within 93-11 or PA64S...... intersubspecific polymorphisms. In our study, we found that the intersubspecific variations of 93-11 (indica) and PA64S (japonica) chloroplast genomes consisted of 72 single nucleotide polymorphisms and 27 insertions or deletions. The intersubspecific polymorphism rates between 93-11 and PA64S were 0.05% for...... single nucleotide polymorphisms and 0.02% for insertions or deletions, nearly 8 and 10 times lower than their respective nuclear genomes. Based on the total number of nucleotide substitutions between the two chloroplast genomes, we dated the divergence of indica and japonica chloroplast genomes as...

  3. Reconstruction of ancestral protein sequences and its applications

    OpenAIRE

    Grishin Nick V; Pei Jimin; Cai Wei

    2004-01-01

    Abstract Background Modern-day proteins were selected during long evolutionary history as descendants of ancient life forms. In silico reconstruction of such ancestral protein sequences facilitates our understanding of evolutionary processes, protein classification and biological function. Additionally, reconstructed ancestral protein sequences could serve to fill in sequence space thus aiding remote homology inference. Results We developed ANCESCON, a package for distance-based phylogenetic ...

  4. Molecular paleontology: a biochemical model of the ancestral ribosome

    OpenAIRE

    Hsiao, Chiaolong; Lenz, Timothy K.; Peters, Jessica K; Fang, Po-Yu; Schneider, Dana M.; Anderson, Eric J.; Preeprem, Thanawadee; Bowman, Jessica C.; O'Neill, Eric B.; Lie, Lively; Athavale, Shreyas S.; Gossett, J. Jared; Trippe, Catherine; Murray, Jason; Anton S. Petrov

    2013-01-01

    Ancient components of the ribosome, inferred from a consensus of previous work, were constructed in silico, in vitro and in vivo. The resulting model of the ancestral ribosome presented here incorporates ∼20% of the extant 23S rRNA and fragments of five ribosomal proteins. We test hypotheses that ancestral rRNA can: (i) assume canonical 23S rRNA-like secondary structure, (ii) assume canonical tertiary structure and (iii) form native complexes with ribosomal protein fragments. Footprinting exp...

  5. Inheritance of chloroplast DNA in Chlamydomonas reinhardtii

    OpenAIRE

    Grant, David M; Nicholas W. Gillham; Boynton, John E.

    1980-01-01

    Two symmetrically located deletions of approximately 100 base pairs each have been identified in chloroplast DNA of Chlamydomonas reinhardtii. Although present in a mutant strain that requires acetate for growth, both deletions have been shown to be distinct from the nonphotosynthetic phenotype of this strain. These physical markers in the chloroplast genome and maternally inherited genetic markers showed strict cotransmission in reciprocal crosses. Thus, our results are consistent with the l...

  6. Identification of CP12 as a Novel Calcium-Binding Protein in Chloroplasts

    Directory of Open Access Journals (Sweden)

    Agostinho Gomes Rocha

    2013-08-01

    Full Text Available Calcium plays an important role in the regulation of several chloroplast processes. However, very little is still understood about the calcium fluxes or calcium-binding proteins present in plastids. Indeed, classical EF-hand containing calcium-binding proteins appears to be mostly absent from plastids. In the present study we analyzed the stroma fraction of Arabidopsis chloroplasts for the presence of novel calcium-binding proteins using 2D-PAGE separation followed by calcium overlay assay. A small acidic protein was identified by mass spectrometry analyses as the chloroplast protein CP12 and the ability of CP12 to bind calcium was confirmed with recombinant proteins. CP12 plays an important role in the regulation of the Calvin-Benson-Bassham Cycle participating in the assembly of a supramolecular complex between phosphoribulokinase and glyceraldehyde 3-phosphate dehydrogenase, indicating that calcium signaling could play a role in regulating carbon fixation.

  7. Evolution of the chloroplast division machinery

    Institute of Scientific and Technical Information of China (English)

    Hongbo GAO; Fuli GAO

    2011-01-01

    Chloroplasts are photosynthetic organelles derived from endosymbiotic cyanobacteria during evolution.Dramatic changes occurred during the process of the formation and evolution of chloroplasts,including the large-scale gene transfer from chloroplast to nucleus.However,there are still many essential characters remaining.For the chloroplast division machinery,FtsZ proteins,Ftn2,SulA and part of the division site positioning system- MinD and MinE are still conserved.New or at least partially new proteins,such as FtsZ family proteins FtsZl and ARC3,ARC6H,ARC5,PDV1,PDV2 and MCD1,were introduced for the division of chloroplasts during evolution.Some bacterial cell division proteins,such as FtsA,MreB,Ftn6,FtsW and Ftsl,probably lost their function or were gradually lost.Thus,the chloroplast division machinery is a dynamically evolving structure with both conservation and innovation.

  8. The diversity and coevolution of Rubisco, plastids, pyrenoids, and chloroplast-based CO{sub 2}-concentrating mechanisms in algae

    Energy Technology Data Exchange (ETDEWEB)

    Badger, M. R.; Andrews, T. J.; Whitney, S. M.; Ludwig, M.; Price, G. D. [Australian National Univ., Research School of Biological Sciences, Canberra, ACT (Australia); Yellowlees, D. C.; Leggat, W. [James Cook Univ., Dept of Biochemistry and Molecular Biology, Townsville, QLD (Australia)

    1998-06-01

    The potential diversity of Rubisco and chloroplast-based carbon dioxide concentrating mechanisms (CCMs) in green and non-green algae are examined. The review emphasized recent advances in understanding the subject and areas with future research potential. In general, the review found that Rubisco enzymes from algae have evolved a higher affinity for carbon dioxide when the algae have adopted a strategy for carbon dioxide fixation that does not utilize a CCM. This appears to be true for both the Green and Red Form I Rubisco enzymes found in green and non-green algae. In some microalgae there is a strong correlation between the existence of a high-affinity CCM physiology and the presence of pyrenoids, suggestive of the potential importance of these chloroplast Rubisco-containing bodies. In contrast, in macroalgae a greater diversity of the apparent relationships between pyrenoids and chloroplast features and the CCM physiology was found. With regard to future research, the function of the pyrenoid and other chloroplast features, the operation of chloroplast-based CCM, and the assessment of the coevolution of Rubisco, appeared to be the most promising areas. 109 refs., 4 tabs., 5 figs.

  9. Glycolate transporter of the pea chloroplast envelope

    International Nuclear Information System (INIS)

    The discovery of a glycolate transporter in the pea (Pisum sativum) chloroplast envelope is described. Several novel silicone oil centrifugation methods were developed to resolve the initial rate kinetics of [14C]glycolate transport by isolated, intact pea chloroplasts. Chloroplast glycolate transport was found to be carrier mediated. Transport rates saturated with increasing glycolate concentration. N-Ethylmaleimide (NEM) pretreatment of chloroplasts inhibited transport, an inhibition prevented by glycolate. Glycolate distributed across the envelope in a way which equalized stromal and medium glycolic acid concentrations, limiting possible transport mechanisms to facilitated glycolic acid diffusion, proton symport or hydroxyl antiport. The effects of stomal and medium pH's on the K/sub m/ and V/sub max/ fit the predictions of mobile carrier kinetic models of hydroxyl antiport or proton symport (H+ binds first). The carrier mediated transport was fast enough to be consistent with in vivo rates of photorespiration. The 2-hydroxymonocarboxylates, glycerate, lactate and glyoxylate are competitive inhibitors of chloroplast glycolate uptake. Glyoxylate, D-lactate and D-glycerate cause glycolate counterflow, indicating that they are also substrates of the glycolate carrier. This finding was confirmed for D-glycerate by studies on glycolate effects on [1-14C]D-glycerate transport

  10. Proteomic Insight into the Response of Arabidopsis Chloroplasts to Darkness

    Science.gov (United States)

    Wang, Jing; Yu, Qingbo; Xiong, Haibo; Wang, Jun; Chen, Sixue; Yang, Zhongnan; Dai, Shaojun

    2016-01-01

    Chloroplast function in photosynthesis is essential for plant growth and development. It is well-known that chloroplasts respond to various light conditions. However, it remains poorly understood about how chloroplasts respond to darkness. In this study, we found 81 darkness-responsive proteins in Arabidopsis chloroplasts under 8 h darkness treatment. Most of the proteins are nucleus-encoded, indicating that chloroplast darkness response is closely regulated by the nucleus. Among them, 17 ribosome proteins were obviously reduced after darkness treatment. The protein expressional patterns and physiological changes revealed the mechanisms in chloroplasts in response to darkness, e.g., (1) inhibition of photosystem II resulted in preferential cyclic electron flow around PSI; (2) promotion of starch degradation; (3) inhibition of chloroplastic translation; and (4) regulation by redox and jasmonate signaling. The results have improved our understanding of molecular regulatory mechanisms in chloroplasts under darkness. PMID:27137770

  11. Protein methylation reactions in intact pea chloroplasts

    International Nuclear Information System (INIS)

    Post-translational protein methylation was investigated in Pisum sativum chloroplasts. Intact pea chloroplasts were incubated with (3H-methyl)-S-adenosylmethionine under various conditions. The chloroplasts were then separated into stromal and thylakoid fractions and analyzed for radioactivity transferred to protein. Light enhanced the magnitude of labeling in both fractions. One thylakoid polypeptide with an apparent molecular mass of 43 kDa was labeled only in the light. Several other thylakoid and stromal proteins were labeled in both light and dark-labeling conditions. Both base-labile methylation, carboxy-methylesters and base-stable groups, N-methylations were found. Further characterization of the methyl-transfer reactions will be presented

  12. Genomics and chloroplast evolution: what did cyanobacteria do for plants?

    OpenAIRE

    Raven, J.A.; Allen, John

    2003-01-01

    The complete genome sequences of cyanobacteria and of the higher plant Arabidopsis thaliana leave no doubt that the plant chloroplast originated, through endosymbiosis, from a cyanobacterium. But the genomic legacy of cyanobacterial ancestry extends far beyond the chloroplast itself, and persists in organisms that have lost chloroplasts completely.

  13. Molecular Evolution of the Substrate Specificity of Chloroplastic Aldolases/Rubisco Lysine Methyltransferases in Plants.

    Science.gov (United States)

    Ma, Sheng; Martin-Laffon, Jacqueline; Mininno, Morgane; Gigarel, Océane; Brugière, Sabine; Bastien, Olivier; Tardif, Marianne; Ravanel, Stéphane; Alban, Claude

    2016-04-01

    Rubisco and fructose-1,6-bisphosphate aldolases (FBAs) are involved in CO2 fixation in chloroplasts. Both enzymes are trimethylated at a specific lysine residue by the chloroplastic protein methyltransferase LSMT. Genes coding LSMT are present in all plant genomes but the methylation status of the substrates varies in a species-specific manner. For example, chloroplastic FBAs are naturally trimethylated in both Pisum sativum and Arabidopsis thaliana, whereas the Rubisco large subunit is trimethylated only in the former species. The in vivo methylation status of aldolases and Rubisco matches the catalytic properties of AtLSMT and PsLSMT, which are able to trimethylate FBAs or FBAs and Rubisco, respectively. Here, we created chimera and site-directed mutants of monofunctional AtLSMT and bifunctional PsLSMT to identify the molecular determinants responsible for substrate specificity. Our results indicate that the His-Ala/Pro-Trp triad located in the central part of LSMT enzymes is the key motif to confer the capacity to trimethylate Rubisco. Two of the critical residues are located on a surface loop outside the methyltransferase catalytic site. We observed a strict correlation between the presence of the triad motif and the in vivo methylation status of Rubisco. The distribution of the motif into a phylogenetic tree further suggests that the ancestral function of LSMT was FBA trimethylation. In a recent event during higher plant evolution, this function evolved in ancestors of Fabaceae, Cucurbitaceae, and Rosaceae to include Rubisco as an additional substrate to the archetypal enzyme. Our study provides insight into mechanisms by which SET-domain protein methyltransferases evolve new substrate specificity. PMID:26785049

  14. Direct Chloroplast Sequencing: Comparison of Sequencing Platforms and Analysis Tools for Whole Chloroplast Barcoding

    OpenAIRE

    Marta Brozynska; Agnelo Furtado; Robert James Henry

    2014-01-01

    Direct sequencing of total plant DNA using next generation sequencing technologies generates a whole chloroplast genome sequence that has the potential to provide a barcode for use in plant and food identification. Advances in DNA sequencing platforms may make this an attractive approach for routine plant identification. The HiSeq (Illumina) and Ion Torrent (Life Technology) sequencing platforms were used to sequence total DNA from rice to identify polymorphisms in the whole chloroplast genom...

  15. Isolation of ancestral sylvatic dengue virus type 1, Malaysia.

    Science.gov (United States)

    Teoh, Boon-Teong; Sam, Sing-Sin; Abd-Jamil, Juraina; AbuBakar, Sazaly

    2010-11-01

    Ancestral sylvatic dengue virus type 1, which was isolated from a monkey in 1972, was isolated from a patient with dengue fever in Malaysia. The virus is neutralized by serum of patients with endemic DENV-1 infection. Rare isolation of this virus suggests a limited spillover infection from an otherwise restricted sylvatic cycle. PMID:21029545

  16. Isolation of Ancestral Sylvatic Dengue Virus Type 1, Malaysia

    OpenAIRE

    Teoh, Boon-Teong; Sam, Sing-Sin; Abd-Jamil, Juraina; AbuBakar, Sazaly

    2010-01-01

    Ancestral sylvatic dengue virus type 1, which was isolated from a monkey in 1972, was isolated from a patient with dengue fever in Malaysia. The virus is neutralized by serum of patients with endemic DENV-1 infection. Rare isolation of this virus suggests a limited spillover infection from an otherwise restricted sylvatic cycle.

  17. Are survival processing memory advantages based on ancestral priorities?

    Science.gov (United States)

    Soderstrom, Nicholas C; McCabe, David P

    2011-06-01

    Recent research has suggested that our memory systems are especially tuned to process information according to its survival relevance, and that inducing problems of "ancestral priorities" faced by our ancestors should lead to optimal recall performance (Nairne & Pandeirada, Cognitive Psychology, 2010). The present study investigated the specificity of this idea by comparing an ancestor-consistent scenario and a modern survival scenario that involved threats that were encountered by human ancestors (e.g., predators) or threats from fictitious creatures (i.e., zombies). Participants read one of four survival scenarios in which the environment and the explicit threat were either consistent or inconsistent with ancestrally based problems (i.e., grasslands-predators, grasslands-zombies, city-attackers, city-zombies), or they rated words for pleasantness. After rating words based on their survival relevance (or pleasantness), the participants performed a free recall task. All survival scenarios led to better recall than did pleasantness ratings, but recall was greater when zombies were the threat, as compared to predators or attackers. Recall did not differ for the modern (i.e., city) and ancestral (i.e., grasslands) scenarios. These recall differences persisted when valence and arousal ratings for the scenarios were statistically controlled as well. These data challenge the specificity of ancestral priorities in survival-processing advantages in memory. PMID:21327372

  18. Energetic cost of protein import across the envelope membranes of chloroplasts.

    Science.gov (United States)

    Shi, Lan-Xin; Theg, Steven M

    2013-01-15

    Chloroplasts are the organelles of green plants in which light energy is transduced into chemical energy, forming ATP and reduced carbon compounds upon which all life depends. The expenditure of this energy is one of the central issues of cellular metabolism. Chloroplasts contain ~3,000 proteins, among which less than 100 are typically encoded in the plastid genome. The rest are encoded in the nuclear genome, synthesized in the cytosol, and posttranslationally imported into the organelle in an energy-dependent process. We report here a measurement of the amount of ATP hydrolyzed to import a protein across the chloroplast envelope membranes--only the second complete accounting of the cost in Gibbs free energy of protein transport to be undertaken. Using two different precursors prepared by three distinct techniques, we show that the import of a precursor protein into chloroplasts is accompanied by the hydrolysis of ~650 ATP molecules. This translates to a ΔG(protein) (transport) of some 27,300 kJ/mol protein imported. We estimate that protein import across the plastid envelope membranes consumes ~0.6% of the total light-saturated energy output of the organelle. PMID:23277572

  19. Photosynthesis in a different light: spectro-microscopy for in vivo characterization of chloroplasts

    OpenAIRE

    Peter, Sébastien; Zell, Martina B.; Blum, Christian; Stuhl, Alexander; Elgass, Kirstin; Sackrow, Marcus; Subramaniam, Vinod; Meixner, Alfred J; Harter, Klaus; Maurino, Veronica G.; Schleifenbaum, Frank E.

    2014-01-01

    During photosynthesis, energy conversion at the two photosystems is controlled by highly complex and dynamic adaptation processes triggered by external factors such as light quality, intensity, and duration, or internal cues such as carbon availability. These dynamics have remained largely concealed so far, because current analytical techniques are based on the investigation of isolated chloroplasts lacking full adaptation ability and are performed at non-physiologically low temperatures. Her...

  20. Glutathionylation of chloroplast thioredoxin f is a redox signaling mechanism in plants

    OpenAIRE

    Michelet, Laure; Zaffagnini, Mirko; Marchand, Christophe; Collin, Valérie; Decottignies, Paulette; Tsan, Pascale; Lancelin, Jean-Marc; Trost, Paolo; Miginiac-Maslow, Myroslawa; Noctor, Graham; Lemaire, Stéphane D.

    2005-01-01

    Thioredoxin f (TRXf) is a key factor in the redox regulation of chloroplastic carbon fixation enzymes, whereas glutathione is an important thiol buffer whose status is modulated by stress conditions. Here, we report specific glutathionylation of TRXf. A conserved cysteine is present in the TRXf primary sequence, in addition to its two active-site cysteines. The additional cysteine becomes glutathionylated when TRXf is exposed to oxidized glutathione or to reduced glutathione plus oxidants. No...

  1. Redox signalling in the chloroplast: structure of oxidized pea fructose-1,6-bisphosphate phosphatase.

    OpenAIRE

    Chiadmi, M.; Navaza, A; Miginiac-Maslow, M; Jacquot, J P; Cherfils, J

    1999-01-01

    Sunlight provides the energy source for the assimilation of carbon dioxide by photosynthesis, but it also provides regulatory signals that switch on specific sets of enzymes involved in the alternation of light and dark metabolisms in chloroplasts. Capture of photons by chlorophyll pigments triggers redox cascades that ultimately activate target enzymes via the reduction of regulatory disulfide bridges by thioredoxins. Here we report the structure of the oxidized, low-activity form of chlorop...

  2. A novel chloroplast-localized protein EMB1303 is required for chloroplast development in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Xiaozhen Huang; Xiaoyan Zhang; Shuhua Yang

    2009-01-01

    To understand the molecular mechanisms underlying chloroplast development, we isolated and characterized the albino mutant emb1303-1 in Arabidopsis. The mutant displayed a severe dwarf phenotype with small albino rosette leaves and short roots on a synthetic medium containing sucrose. It is pigment-deficient and seedling lethal when grown in soil. Embryo development was delayed in the mutant, although seed germination was not significantly im-paired. The plastids of emb1303-1 were arrested in early developmental stages without the classical stack of thylakoid membrane. Genetic and molecular analyses uncovered that the EMB1303 gene encodes a novel chloroplast-localized protein. Mieroarray and RT-PCR analyses revealed that a number of nuclear-and plastid-encoded genes involved in photosynthesis and chloroplast biogenesis were substantially downregulated in the mutant. Moreover, the accu-mulation of several major chloroplast proteins was severely compromised in emb1303-1. These results suggest that EMBI303 is essential for chloroplast development.

  3. Direct chloroplast sequencing: comparison of sequencing platforms and analysis tools for whole chloroplast barcoding.

    Directory of Open Access Journals (Sweden)

    Marta Brozynska

    Full Text Available Direct sequencing of total plant DNA using next generation sequencing technologies generates a whole chloroplast genome sequence that has the potential to provide a barcode for use in plant and food identification. Advances in DNA sequencing platforms may make this an attractive approach for routine plant identification. The HiSeq (Illumina and Ion Torrent (Life Technology sequencing platforms were used to sequence total DNA from rice to identify polymorphisms in the whole chloroplast genome sequence of a wild rice plant relative to cultivated rice (cv. Nipponbare. Consensus chloroplast sequences were produced by mapping sequence reads to the reference rice chloroplast genome or by de novo assembly and mapping of the resulting contigs to the reference sequence. A total of 122 polymorphisms (SNPs and indels between the wild and cultivated rice chloroplasts were predicted by these different sequencing and analysis methods. Of these, a total of 102 polymorphisms including 90 SNPs were predicted by both platforms. Indels were more variable with different sequencing methods, with almost all discrepancies found in homopolymers. The Ion Torrent platform gave no apparent false SNP but was less reliable for indels. The methods should be suitable for routine barcoding using appropriate combinations of sequencing platform and data analysis.

  4. The chloroplast genome sequence of the green alga Leptosira terrestris: multiple losses of the inverted repeat and extensive genome rearrangements within the Trebouxiophyceae

    Directory of Open Access Journals (Sweden)

    Turmel Monique

    2007-07-01

    Full Text Available Abstract Background In the Chlorophyta – the green algal phylum comprising the classes Prasinophyceae, Ulvophyceae, Trebouxiophyceae and Chlorophyceae – the chloroplast genome displays a highly variable architecture. While chlorophycean chloroplast DNAs (cpDNAs deviate considerably from the ancestral pattern described for the prasinophyte Nephroselmis olivacea, the degree of remodelling sustained by the two ulvophyte cpDNAs completely sequenced to date is intermediate relative to those observed for chlorophycean and trebouxiophyte cpDNAs. Chlorella vulgaris (Chlorellales is currently the only photosynthetic trebouxiophyte whose complete cpDNA sequence has been reported. To gain insights into the evolutionary trends of the chloroplast genome in the Trebouxiophyceae, we sequenced cpDNA from the filamentous alga Leptosira terrestris (Ctenocladales. Results The 195,081-bp Leptosira chloroplast genome resembles the 150,613-bp Chlorella genome in lacking a large inverted repeat (IR but differs greatly in gene order. Six of the conserved genes present in Chlorella cpDNA are missing from the Leptosira gene repertoire. The 106 conserved genes, four introns and 11 free standing open reading frames (ORFs account for 48.3% of the genome sequence. This is the lowest gene density yet observed among chlorophyte cpDNAs. Contrary to the situation in Chlorella but similar to that in the chlorophycean Scenedesmus obliquus, the gene distribution is highly biased over the two DNA strands in Leptosira. Nine genes, compared to only three in Chlorella, have significantly expanded coding regions relative to their homologues in ancestral-type green algal cpDNAs. As observed in chlorophycean genomes, the rpoB gene is fragmented into two ORFs. Short repeats account for 5.1% of the Leptosira genome sequence and are present mainly in intergenic regions. Conclusion Our results highlight the great plasticity of the chloroplast genome in the Trebouxiophyceae and indicate

  5. Multiway admixture deconvolution using phased or unphased ancestral panels.

    Science.gov (United States)

    Churchhouse, Claire; Marchini, Jonathan

    2013-01-01

    We describe a novel method for inferring the local ancestry of admixed individuals from dense genome-wide single nucleotide polymorphism data. The method, called MULTIMIX, allows multiple source populations, models population linkage disequilibrium between markers and is applicable to datasets in which the sample and source populations are either phased or unphased. The model is based upon a hidden Markov model of switches in ancestry between consecutive windows of loci. We model the observed haplotypes within each window using a multivariate normal distribution with parameters estimated from the ancestral panels. We present three methods to fit the model-Markov chain Monte Carlo sampling, the Expectation Maximization algorithm, and a Classification Expectation Maximization algorithm. The performance of our method on individuals simulated to be admixed with European and West African ancestry shows it to be comparable to HAPMIX, the ancestry calls of the two methods agreeing at 99.26% of loci across the three parameter groups. In addition to it being faster than HAPMIX, it is also found to perform well over a range of extent of admixture in a simulation involving three ancestral populations. In an analysis of real data, we estimate the contribution of European, West African and Native American ancestry to each locus in the Mexican samples of HapMap, giving estimates of ancestral proportions that are consistent with those previously reported. PMID:23136122

  6. Origin of a chloroplast protein importer

    OpenAIRE

    Bölter, Bettina; Soll, Jürgen; Schulz, Alexander; Hinnah, Silke; Wagner, Richard

    1998-01-01

    During evolution, chloroplasts have relinquished the majority of their genes to the nucleus. The products of transferred genes are imported into the organelle with the help of an import machinery that is distributed across the inner and outer plastid membranes. The evolutionary origin of this machinery is puzzling because, in the putative predecessors, the cyanobacteria, the outer two membranes, the plasma membrane, and the lipopolysaccharide layer lack a functionally similar protein import s...

  7. Evidence for a respiratory chain in the chloroplast

    OpenAIRE

    Bennoun, Pierre

    1982-01-01

    Evidence is given for the existence of an electron transport pathway to oxygen in the thylakoid membranes of chloroplasts (chlororespiration). Plastoquinone is shown to be a redox carrier common to both photosynthetic and chlororespiratory pathways. It is shown that, in dark-adapted chloroplasts, an electrochemical gradient is built up across the thylakoid membrane by transfer of electrons through the chlororespiratory chain as well as by reverse functioning of the chloroplast ATPases. It is ...

  8. Expressing PHB synthetic genes through chloroplast genetic engineering

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Chloroplast integration and expression vector containing expression cassettes for phbB, phbA, phbC and aadA genes was constructed and bombarded into the tobacco chloroplast genome. Transplastomic plants were analyzed with PCR and Southern blot. Their homoplastomy was also judged. Northern dot and RT-PCR analysis were employed to investigate transgene expression at transcriptional level. The results indicate that the chloroplast transformation system is compatible for poly-3-hydroxybutyrate (PHB) production.

  9. Ancestral gene and "complementary" antibody dominate early ontogeny.

    Science.gov (United States)

    Arend, Peter

    2013-05-01

    According to N.K. Jerne the somatic generation of immune recognition occurs in conjunction with germ cell evolution and precedes the formation of the zygote, i.e. operates before clonal selection. We propose that it is based on interspecies inherent, ancestral forces maintaining the lineage. Murine oogenesis may be offered as a model. So in C57BL/10BL sera an anti-A reactive, mercapto-ethanol sensitive glycoprotein of up to now unknown cellular origin, but exhibiting immunoglobulin M character, presents itself "complementary" to a syngeneic epitope, which encoded by histocompatibility gene A or meanwhile accepted ancestor of the ABO gene family, arises predominantly in ovarian tissue and was detected statistically significant exclusively in polar glycolipids. Reports either on loss, pronounced expressions or de novo appearances of A-type structures in various conditions of accelerated growth like germ cell evolution, wound healing, inflammation and tumor proliferation in man and ABO related animals might show the dynamics of ancestral functions guarantying stem cell fidelity in maturation and tissue renewal processes. Procedures vice versa generating pluripotent stem cells for therapeutical reasons may indicate, that any artificially started growth should somehow pass through the germ line from the beginning, where according to growing knowledge exclusively the oocyte's genome provides a completely channeling ancestral information. In predatory animals such as the modern-day sea anemone, ancestral proteins, particularly those of the p53 gene family govern the reproduction processes, and are active up to the current mammalian female germ line. Lectins, providing the dual function of growth promotion and defense in higher plants, are suggested to represent the evolutionary precursors of the mammalian immunoglobulin M molecules, or protein moiety implying the greatest functional diversity in nature. And apart from any established mammalian genetic tree, a common vetch

  10. Complex chloroplast RNA metabolism: just debugging the genetic programme?

    Directory of Open Access Journals (Sweden)

    Schmitz-Linneweber Christian

    2008-08-01

    Full Text Available Abstract Background The gene expression system of chloroplasts is far more complex than that of their cyanobacterial progenitor. This gain in complexity affects in particular RNA metabolism, specifically the transcription and maturation of RNA. Mature chloroplast RNA is generated by a plethora of nuclear-encoded proteins acquired or recruited during plant evolution, comprising additional RNA polymerases and sigma factors, and sequence-specific RNA maturation factors promoting RNA splicing, editing, end formation and translatability. Despite years of intensive research, we still lack a comprehensive explanation for this complexity. Results We inspected the available literature and genome databases for information on components of RNA metabolism in land plant chloroplasts. In particular, new inventions of chloroplast-specific mechanisms and the expansion of some gene/protein families detected in land plants lead us to suggest that the primary function of the additional nuclear-encoded components found in chloroplasts is the transgenomic suppression of point mutations, fixation of which occurred due to an enhanced genetic drift exhibited by chloroplast genomes. We further speculate that a fast evolution of transgenomic suppressors occurred after the water-to-land transition of plants. Conclusion Our inspections indicate that several chloroplast-specific mechanisms evolved in land plants to remedy point mutations that occurred after the water-to-land transition. Thus, the complexity of chloroplast gene expression evolved to guarantee the functionality of chloroplast genetic information and may not, with some exceptions, be involved in regulatory functions.

  11. Nanophotonics of Chloroplasts for Bio-Inspired Solar Energy Materials

    Science.gov (United States)

    Gourley, Paul L.; Gourley, Cheryl R.

    2011-03-01

    In the search for new energy sources, lessons can be learned from chloroplast photonics. The nano-architecture of chloroplasts is remarkably well-adapted to mediate sunlight interactions for efficient energy conversion. We carried out experiments with chloroplasts isolated from spinach and leaf lettuce to elucidate the relationship between nano-architecture, biomolecular composition and photonic properties. We obtained high-resolution microscopic images of single chloroplasts to identify geometries of chloroplasts and interior grana. We performed micro-spectroscopy to identify strengths of absorption and fluorescence transitions and related them to broadband reflectance and transmittance spectra of whole leaf structures. Finally, the nonlinear optical properties were investigated with nanolaser spectroscopy by placing chloroplasts into micro-resonators and optically pumping. These spectra reveal chloroplast photonic modes and allow measurement of single chloroplast light scattering cross section, polarizability, and refractive index. The nanolaser spectra recorded at increasing pump powers enabled us to observe non-linear optics, photon dynamics, and stimulated emission from single chloroplasts. All of these experiments provide insight into plant photonics and inspiration of paradigms for synthetic biomaterials to harness sunlight in new ways.

  12. Photosynthetic 14C fixation in leaves and isolated chloroplasts of some scrub species under the influence of paraquat and 2,4,5-T

    International Nuclear Information System (INIS)

    The diurnal course of carbon dioxide uptake in the leaves of six nonsucculent semiarid scrub species was investigated. Five nonsucculent scrub species, Carissa spinarum, Maba buxifolia, Flacourtia sepiaria, Gymnosporia emerginata and Dodonaea viscosa exhibited nocturnal carbon assimilation while day time CO2 uptake was predominant in Chomelia asiatica. Foliar application of paraquat (100 mg 1sup(-1)) or 2,4,5-T (2000 mg 1sup(-1)) caused a marked inhibition in the dark uptake of CO2. On the other hand, carbon uptake during day was slightly reduced. Studies on the carbon assimilation of isolated chloroplasts under the influence of paraquat or 2,4,5-T revealed that paraquat is more effective than 2,4,5-T in the suppression of carbon assimilation of in vivo and in vitro chloroplasts. The data suggested that the process of nocturnal carbon assimilation is far more sensitive to paraquat than the light dependent carbon fixation during day. (author)

  13. Ancestral Origins and Genetic History of Tibetan Highlanders.

    Science.gov (United States)

    Lu, Dongsheng; Lou, Haiyi; Yuan, Kai; Wang, Xiaoji; Wang, Yuchen; Zhang, Chao; Lu, Yan; Yang, Xiong; Deng, Lian; Zhou, Ying; Feng, Qidi; Hu, Ya; Ding, Qiliang; Yang, Yajun; Li, Shilin; Jin, Li; Guan, Yaqun; Su, Bing; Kang, Longli; Xu, Shuhua

    2016-09-01

    The origin of Tibetans remains one of the most contentious puzzles in history, anthropology, and genetics. Analyses of deeply sequenced (30×-60×) genomes of 38 Tibetan highlanders and 39 Han Chinese lowlanders, together with available data on archaic and modern humans, allow us to comprehensively characterize the ancestral makeup of Tibetans and uncover their origins. Non-modern human sequences compose ∼6% of the Tibetan gene pool and form unique haplotypes in some genomic regions, where Denisovan-like, Neanderthal-like, ancient-Siberian-like, and unknown ancestries are entangled and elevated. The shared ancestry of Tibetan-enriched sequences dates back to ∼62,000-38,000 years ago, predating the Last Glacial Maximum (LGM) and representing early colonization of the plateau. Nonetheless, most of the Tibetan gene pool is of modern human origin and diverged from that of Han Chinese ∼15,000 to ∼9,000 years ago, which can be largely attributed to post-LGM arrivals. Analysis of ∼200 contemporary populations showed that Tibetans share ancestry with populations from East Asia (∼82%), Central Asia and Siberia (∼11%), South Asia (∼6%), and western Eurasia and Oceania (∼1%). Our results support that Tibetans arose from a mixture of multiple ancestral gene pools but that their origins are much more complicated and ancient than previously suspected. We provide compelling evidence of the co-existence of Paleolithic and Neolithic ancestries in the Tibetan gene pool, indicating a genetic continuity between pre-historical highland-foragers and present-day Tibetans. In particular, highly differentiated sequences harbored in highlanders' genomes were most likely inherited from pre-LGM settlers of multiple ancestral origins (SUNDer) and maintained in high frequency by natural selection. PMID:27569548

  14. Genetic population structure of the desert shrub species lycium ruthenicum inferred from chloroplast dna

    International Nuclear Information System (INIS)

    Lycium ruthenicum (Solananeae), a spiny shrub mostly distributed in the desert regions of north and northwest China, has been shown to exhibit high tolerance to the extreme environment. In this study, the phylogeography and evolutionary history of L. ruthenicum were examined, on the basis of 80 individuals from eight populations. Using the sequence variations of two spacer regions of chloroplast DNA (trnH-psbA and rps16-trnK) , the absence of a geographic component in the chloroplast DNA genetic structure was identified (GST = 0.351, NST = 0.304, NST< GST), which was consisted with the result of SAMOVA, suggesting weak phylogeographic structure of this species. Phylogenetic and network analyses showed that a total of 10 haplotypes identified in the present study clustered into two clades, in which clade I harbored the ancestral haplotypes that inferred two independent glacial refugia in the middle of Qaidam Basin and the western Inner Mongolia. The existence of regional evolutionary differences was supported by GENETREE, which revealed that one of the population in Qaidam Basin and the two populations in Tarim Basin had experienced rapid expansion, and the other populations retained relatively stable population size during the Pleistocene . Given the results of long-term gene flow and pairwise differences, strong gene flow was insufficient to reduce the genetic differentiation among populations or within populations, probably due to the genetic composition containing a common haplotype and the high number of private haplotypes fixed for most of the population. The divergence times of different lineages were consistent with the rapid uplift phases of the Qinghai-Tibetan Plateau and the initiation and expansion of deserts in northern China, suggesting that the origin and evolution of L. ruthenicum were strongly influenced by Quaternary environment changes. (author)

  15. Tools for regulated gene expression in the chloroplast of Chlamydomonas.

    Science.gov (United States)

    Rochaix, Jean-David; Surzycki, Raymond; Ramundo, Silvia

    2014-01-01

    The green unicellular alga Chlamydomonas reinhardtii has emerged as a very attractive model system for chloroplast genetic engineering. Algae can be transformed readily at the chloroplast level through bombardment of cells with a gene gun, and transformants can be selected using antibiotic resistance or phototrophic growth. An inducible chloroplast gene expression system could be very useful for several reasons. First, it could be used to elucidate the function of essential chloroplast genes required for cell growth and survival. Second, it could be very helpful for expressing proteins which are toxic to the algal cells. Third, it would allow for the reversible depletion of photosynthetic complexes thus making it possible to study their biogenesis in a controlled fashion. Fourth, it opens promising possibilities for hydrogen production in Chlamydomonas. Here we describe an inducible/repressible chloroplast gene expression system in Chlamydomonas in which the copper-regulated Cyc6 promoter drives the expression of the nuclear Nac2 gene encoding a protein which is targeted to the chloroplast where it acts specifically on the chloroplast psbD 5'-untranslated region and is required for the stable accumulation of the psbD mRNA and photosystem II. The system can be used for any chloroplast gene or transgene by placing it under the control of the psbD 5'-untranslated region. PMID:24599871

  16. Chloroplast division during leaf development of Xanthium pensylvanicum Wallr. (Compositae

    Directory of Open Access Journals (Sweden)

    Roman Maksymowych

    2014-02-01

    Full Text Available Division and growth of chloroplasts was studied during leaf development of Xanthium pensylvanicum at various stages of development represented by the leaf plastochron index.Between leaf plastochron indices -1.00 and 2.56 chloroplast division was observed with little enlargement. Between 2.50 and 5.00 chloroplasts enlarged in diameter with an average rate of 0.21 µm per day. At leaf plastochron index 5.00 chloroplasts attained their mature size of 6.12 µm. No chloroplast division was found after leaf plastochron index 2.50. A change in shape of plastids from spherical proplastids to discoidal accompanied their growth during stages 2.50 and 5.00.

  17. The complete chloroplast genome of the Dendrobium strongylanthum (Orchidaceae: Epidendroideae).

    Science.gov (United States)

    Li, Jing; Chen, Chen; Wang, Zhe-Zhi

    2016-07-01

    Complete chloroplast genome sequence is very useful for studying the phylogenetic and evolution of species. In this study, the complete chloroplast genome of Dendrobium strongylanthum was constructed from whole-genome Illumina sequencing data. The chloroplast genome is 153 058 bp in length with 37.6% GC content and consists of two inverted repeats (IRs) of 26 316 bp. The IR regions are separated by large single-copy region (LSC, 85 836 bp) and small single-copy (SSC, 14 590 bp) region. A total of 130 chloroplast genes were successfully annotated, including 84 protein coding genes, 38 tRNA genes, and eight rRNA genes. Phylogenetic analyses showed that the chloroplast genome of Dendrobium strongylanthum is related to that of the Dendrobium officinal. PMID:26153739

  18. Fast phylogeny reconstruction through learning of ancestral sequences

    CERN Document Server

    Mihaescu, Radu; Rao, Satish

    2008-01-01

    Given natural limitations on the length DNA sequences, designing phylogenetic reconstruction methods which are reliable under limited information is a crucial endeavor. There have been two approaches to this problem: reconstructing partial but reliable information about the tree (\\cite{Mo07, DMR08,DHJ06,GMS08}), and reaching "deeper" in the tree through reconstruction of ancestral sequences. In the latter category, \\cite{DMR06} settled an important conjecture of M.Steel, showing that, under the CFN model of evolution, all trees on $n$ leaves with edge lengths bounded by the Ising model phase transition can be recovered with high probability from genomes of length $O(\\log n)$ with a polynomial time algorithm. Their methods had a running time of $O(n^{10})$. Here we enhance our methods from \\cite{DHJ06} with the learning of ancestral sequences and provide an algorithm for reconstructing a sub-forest of the tree which is reliable given available data, without requiring a-priori known bounds on the edge lengths o...

  19. The ancestral process of long term seed bank models

    CERN Document Server

    Blath, Jochen; Kurt, Noemi; Spanò, Dario

    2012-01-01

    We present a new model for the evolution of genetic types in the presence of so-called seed banks, i.e., where individuals may obtain their genetic type from ancestors which have lived in the near as well as the very far past. The classical Wright-Fisher model, as well as a seed bank model with bounded age distribution considered by Kaj, Krone and Lascoux (2001) are special cases of our model. We discern three parameter regimes of the seed bank age distribution, which lead to substantially different behaviour in terms of genetic variability, in particular with respect to fixation of types and time to the most recent common ancestor. We prove that for age distributions with finite mean, the rescaled ancestral process converges to a time-changed Kingman coalescent, while in the case of infinite mean, ancestral lineages might not merge at all with positive probability. Further, we present a construction of the forward in time process in equilibrium. The mathematical methods are based on renewal theory, the urn p...

  20. The complete chloroplast genome sequence of Citrus sinensis (L. Osbeck var 'Ridge Pineapple': organization and phylogenetic relationships to other angiosperms

    Directory of Open Access Journals (Sweden)

    Jansen Robert K

    2006-09-01

    Full Text Available Abstract Background The production of Citrus, the largest fruit crop of international economic value, has recently been imperiled due to the introduction of the bacterial disease Citrus canker. No significant improvements have been made to combat this disease by plant breeding and nuclear transgenic approaches. Chloroplast genetic engineering has a number of advantages over nuclear transformation; it not only increases transgene expression but also facilitates transgene containment, which is one of the major impediments for development of transgenic trees. We have sequenced the Citrus chloroplast genome to facilitate genetic improvement of this crop and to assess phylogenetic relationships among major lineages of angiosperms. Results The complete chloroplast genome sequence of Citrus sinensis is 160,129 bp in length, and contains 133 genes (89 protein-coding, 4 rRNAs and 30 distinct tRNAs. Genome organization is very similar to the inferred ancestral angiosperm chloroplast genome. However, in Citrus the infA gene is absent. The inverted repeat region has expanded to duplicate rps19 and the first 84 amino acids of rpl22. The rpl22 gene in the IRb region has a nonsense mutation resulting in 9 stop codons. This was confirmed by PCR amplification and sequencing using primers that flank the IR/LSC boundaries. Repeat analysis identified 29 direct and inverted repeats 30 bp or longer with a sequence identity ≥ 90%. Comparison of protein-coding sequences with expressed sequence tags revealed six putative RNA edits, five of which resulted in non-synonymous modifications in petL, psbH, ycf2 and ndhA. Phylogenetic analyses using maximum parsimony (MP and maximum likelihood (ML methods of a dataset composed of 61 protein-coding genes for 30 taxa provide strong support for the monophyly of several major clades of angiosperms, including monocots, eudicots, rosids and asterids. The MP and ML trees are incongruent in three areas: the position of Amborella and

  1. Chloroplast DNA sequence of the green alga Oedogonium cardiacum (Chlorophyceae: Unique genome architecture, derived characters shared with the Chaetophorales and novel genes acquired through horizontal transfer

    Directory of Open Access Journals (Sweden)

    Lemieux Claude

    2008-06-01

    Full Text Available Abstract Background To gain insight into the branching order of the five main lineages currently recognized in the green algal class Chlorophyceae and to expand our understanding of chloroplast genome evolution, we have undertaken the sequencing of chloroplast DNA (cpDNA from representative taxa. The complete cpDNA sequences previously reported for Chlamydomonas (Chlamydomonadales, Scenedesmus (Sphaeropleales, and Stigeoclonium (Chaetophorales revealed tremendous variability in their architecture, the retention of only few ancestral gene clusters, and derived clusters shared by Chlamydomonas and Scenedesmus. Unexpectedly, our recent phylogenies inferred from these cpDNAs and the partial sequences of three other chlorophycean cpDNAs disclosed two major clades, one uniting the Chlamydomonadales and Sphaeropleales (CS clade and the other uniting the Oedogoniales, Chaetophorales and Chaetopeltidales (OCC clade. Although molecular signatures provided strong support for this dichotomy and for the branching of the Oedogoniales as the earliest-diverging lineage of the OCC clade, more data are required to validate these phylogenies. We describe here the complete cpDNA sequence of Oedogonium cardiacum (Oedogoniales. Results Like its three chlorophycean homologues, the 196,547-bp Oedogonium chloroplast genome displays a distinctive architecture. This genome is one of the most compact among photosynthetic chlorophytes. It has an atypical quadripartite structure, is intron-rich (17 group I and 4 group II introns, and displays 99 different conserved genes and four long open reading frames (ORFs, three of which are clustered in the spacious inverted repeat of 35,493 bp. Intriguingly, two of these ORFs (int and dpoB revealed high similarities to genes not usually found in cpDNA. At the gene content and gene order levels, the Oedogonium genome most closely resembles its Stigeoclonium counterpart. Characters shared by these chlorophyceans but missing in members

  2. Posttranslational Modifications of FERREDOXIN-NADP+ OXIDOREDUCTASE in Arabidopsis Chloroplasts1[W][OPEN

    Science.gov (United States)

    Lehtimäki, Nina; Koskela, Minna M.; Dahlström, Käthe M.; Pakula, Eveliina; Lintala, Minna; Scholz, Martin; Hippler, Michael; Hanke, Guy T.; Rokka, Anne; Battchikova, Natalia; Salminen, Tiina A.; Mulo, Paula

    2014-01-01

    Rapid responses of chloroplast metabolism and adjustments to photosynthetic machinery are of utmost importance for plants’ survival in a fluctuating environment. These changes may be achieved through posttranslational modifications of proteins, which are known to affect the activity, interactions, and localization of proteins. Recent studies have accumulated evidence about the crucial role of a multitude of modifications, including acetylation, methylation, and glycosylation, in the regulation of chloroplast proteins. Both of the Arabidopsis (Arabidopsis thaliana) leaf-type FERREDOXIN-NADP+ OXIDOREDUCTASE (FNR) isoforms, the key enzymes linking the light reactions of photosynthesis to carbon assimilation, exist as two distinct forms with different isoelectric points. We show that both AtFNR isoforms contain multiple alternative amino termini and undergo light-responsive addition of an acetyl group to the α-amino group of the amino-terminal amino acid of proteins, which causes the change in isoelectric point. Both isoforms were also found to contain acetylation of a conserved lysine residue near the active site, while no evidence for in vivo phosphorylation or glycosylation was detected. The dynamic, multilayer regulation of AtFNR exemplifies the complex regulatory network systems controlling chloroplast proteins by a range of posttranslational modifications, which continues to emerge as a novel area within photosynthesis research. PMID:25301888

  3. Global Alignment of Molecular Sequences via Ancestral State Reconstruction

    CERN Document Server

    Andoni, Alexandr; Hassidim, Avinatan; Roch, Sebastien

    2009-01-01

    Molecular phylogenetic techniques do not generally account for such common evolutionary events as site insertions and deletions (known as indels). Instead tree building algorithms and ancestral state inference procedures typically rely on substitution-only models of sequence evolution. In practice these methods are extended beyond this simplified setting with the use of heuristics that produce global alignments of the input sequences--an important problem which has no rigorous model-based solution. In this paper we consider a new version of the multiple sequence alignment in the context of stochastic indel models. More precisely, we introduce the following {\\em trace reconstruction problem on a tree} (TRPT): a binary sequence is broadcast through a tree channel where we allow substitutions, deletions, and insertions; we seek to reconstruct the original sequence from the sequences received at the leaves of the tree. We give a recursive procedure for this problem with strong reconstruction guarantees at low mut...

  4. Haplotype ancestral AH8.1 dans la mucoviscidose

    OpenAIRE

    Beucher, Julie

    2012-01-01

    La mucoviscidose est une maladie à transmission autosomique récessive, due à des mutations du gène CFTR. Les patients, partageant de mêmes mutations de CFTR et un même environnement, ont une expression phénotypique variable, suggérant l'influence d'autres gènes modifiant la sévérité de la maladie, appelés gènes modificateurs. L'atteinte respiratoire, caractérisée par une inflammation exacerbée, est un facteur principal de morbimortalité. L'haplotype ancestral AH8.1, impliqué dans la réponse i...

  5. Ancestral genome inference using a genetic algorithm approach.

    Science.gov (United States)

    Gao, Nan; Yang, Ning; Tang, Jijun

    2013-01-01

    Recent advancement of technologies has now made it routine to obtain and compare gene orders within genomes. Rearrangements of gene orders by operations such as reversal and transposition are rare events that enable researchers to reconstruct deep evolutionary histories. An important application of genome rearrangement analysis is to infer gene orders of ancestral genomes, which is valuable for identifying patterns of evolution and for modeling the evolutionary processes. Among various available methods, parsimony-based methods (including GRAPPA and MGR) are the most widely used. Since the core algorithms of these methods are solvers for the so called median problem, providing efficient and accurate median solver has attracted lots of attention in this field. The "double-cut-and-join" (DCJ) model uses the single DCJ operation to account for all genome rearrangement events. Because mathematically it is much simpler than handling events directly, parsimony methods using DCJ median solvers has better speed and accuracy. However, the DCJ median problem is NP-hard and although several exact algorithms are available, they all have great difficulties when given genomes are distant. In this paper, we present a new algorithm that combines genetic algorithm (GA) with genomic sorting to produce a new method which can solve the DCJ median problem in limited time and space, especially in large and distant datasets. Our experimental results show that this new GA-based method can find optimal or near optimal results for problems ranging from easy to very difficult. Compared to existing parsimony methods which may severely underestimate the true number of evolutionary events, the sorting-based approach can infer ancestral genomes which are much closer to their true ancestors. The code is available at http://phylo.cse.sc.edu. PMID:23658708

  6. Phylogeny of the quadriflagellate Volvocales (Chlorophyceae) based on chloroplast multigene sequences.

    Science.gov (United States)

    Nozaki, Hisayoshi; Misumi, Osami; Kuroiwa, Tsuneyoshi

    2003-10-01

    Since the phylogenetic relationships of the green plants (green algae and land plants) have been extensively studied using 18S ribosomal RNA sequences, change in the arrangement of basal bodies in flagellate cells is considered to be one of the major evolutionary events in the green plants. However, the phylogenetic relationships between biflagellate and quadriflagellate species within the Volvocales remain uncertain. This study examined the phylogeny of three genera of quadriflagellate Volvocales (Carteria, Pseudocarteria, and Hafniomonas) using concatenated sequences from three chloroplast genes. Using these multigene sequences, all three quadriflagellate genera were basal to other members (biflagellates) of the CW (clockwise) group (the Volvocales and their relatives, the Chlorophyceae) and formed three robust clades. Since the flagellar apparatuses of these three quadriflagellate lineages are diverse, including counter clockwise (CCW) and CW orientation of the basal bodies, the CW orientation of the basal bodies might have evolved from the CCW orientation in the ancestral quadriflagellate volvocalean algae, giving rise to the biflagellates, major members of the CW group. PMID:12967607

  7. Gibberellin metabolism in chloroplasts of Pisum sativum L. var. Alaska

    International Nuclear Information System (INIS)

    Little is known about the metabolic control of gibberellin (GA) biosynthesis in higher plants. Recent studies have implicated chloroplasts in the metabolic control of GA metabolism in leaves. Thus chloroplasts from several higher plants have been shown to possess high levels of GA-like activity and appear to be able to localize certain GAs selectivity whilst allowing others to migrate into the cytoplasm. This paper evaluates the ability of chloroplasts to synthesize and interconvert GAs, in an in vitro system developed from plastids of Pisum sativum. The results of detailed analysis of the products are reported

  8. The complete chloroplast genome of Capsicum frutescens (Solanaceae) 1

    OpenAIRE

    Shim, Donghwan; Raveendar, Sebastin; Lee, Jung-Ro; Lee, Gi-An; Ro, Na-Young; Jeon, Young-Ah; Cho, Gyu-Taek; Lee, Ho-Sun; Ma, Kyung-Ho; Chung, Jong-Wook

    2016-01-01

    Premise of the study: We report the complete sequence of the chloroplast genome of Capsicum frutescens (Solanaceae), a species of chili pepper. Methods and Results: Using an Illumina platform, we sequenced the chloroplast genome of C. frutescens. The total length of the genome is 156,817 bp, and the overall GC content is 37.7%. A pair of 25,792-bp inverted repeats is separated by small (17,853 bp) and large (87,380 bp) single-copy regions. The C. frutescens chloroplast genome encodes 132 uniq...

  9. Reactive Nitrogen Species-Dependent Effects on Soybean Chloroplasts

    OpenAIRE

    Puntarulo, Susana; Jasid, Sebastián; Simontacchi, Marcela

    2007-01-01

    Nitric oxide (NO) generation by soybean (Glycine max, var ADM 4800) chloroplasts was studied by electron paramagnetic resonance (EPR) spin-trapping technique.1 Both nitrite and L-arginine (arg) are the required substrates for enzymatic activities considered as possible sources of NO in plants. Soybean chloroplasts showed a NO production of 3.2 ± 0.2 nmol min−1 mg−1 protein in the presence of 1 mM NaNO2. Chloroplasts incubated with 1 mM arg showed a NO production of 0.76 ± 0.04 nmol min−1 mg−1...

  10. Construction and molecular analysis of genetically modified C 3 plants expressing a glycolate oxidizing pathway inside the chloroplast

    OpenAIRE

    Kebeish, Rashad Mohamed Ahmed

    2006-01-01

    Metabolism of glycolate via the photorespiratory pathway in C3 plants consumes not only ATP and reducing equivalents but results also in approximately 25% loss of the carbon from glycolate. In the present study, a novel biochemical pathway for the metabolism of glycolate was established in the chloroplast of Arabidopsis thaliana plants. The new pathway aims to increase the CO2 concentration in the vicinity of Rubisco thereby suppressing photorespiration in C3 plants. The pathway is derived fr...

  11. Origins of prokaryotes, eukaryotes, mitochondria, and chloroplasts

    Science.gov (United States)

    Schwartz, R. M.; Dayhoff, M. O.

    1978-01-01

    A computer branching model is used to analyze cellular evolution. Attention is given to certain key amino acids and nucleotide residues (ferredoxin, 5s ribosomal RNA, and c-type cytochromes) because of their commonality over a wide variety of cell types. Each amino acid or nucleotide residue is a sequence in an inherited biological trait; and the branching method is employed to align sequences so that changes reflect substitution of one residue for another. Based on the computer analysis, the symbiotic theory of cellular evolution is considered the most probable. This theory holds that organelles, e.g., mitochondria and chloroplasts invaded larger bodies, e.g., bacteria, and combined functions to form eucaryotic cells.

  12. Dynamics of chloroplast genomes in green plants.

    Science.gov (United States)

    Xu, Jian-Hong; Liu, Qiuxiang; Hu, Wangxiong; Wang, Tingzhang; Xue, Qingzhong; Messing, Joachim

    2015-10-01

    Chloroplasts are essential organelles, in which genes have widely been used in the phylogenetic analysis of green plants. Here, we took advantage of the breadth of plastid genomes (cpDNAs) sequenced species to investigate their dynamic changes. Our study showed that gene rearrangements occurred more frequently in the cpDNAs of green algae than in land plants. Phylogenetic trees were generated using 55 conserved protein-coding genes including 33 genes for photosynthesis, 16 ribosomal protein genes and 6 other genes, which supported the monophyletic evolution of vascular plants, land plants, seed plants, and angiosperms. Moreover, we could show that seed plants were more closely related to bryophytes rather than pteridophytes. Furthermore, the substitution rate for cpDNA genes was calculated to be 3.3×10(-10), which was almost 10 times lower than genes of nuclear genomes, probably because of the plastid homologous recombination machinery. PMID:26206079

  13. Transport of Ions Across the Inner Envelope Membrane of Chloroplasts

    International Nuclear Information System (INIS)

    The technical report outlines the results of nine years of research on how ions cross the inner envelope membrane of chloroplasts. The ions include protons, nitrite, calcium and ferrous iron. Bicarbonate transport was also studied

  14. Chloroplast genome variation in upland and lowland switchgrass

    Science.gov (United States)

    Switchgrass (Panicum virgatum L.) exists at multiple ploidies and two phenotypically distinct ecotypes. To facilitate interploidal comparisons and to understand the extent of sequence variation within existing breeding pools, two complete switchgrass chloroplast genomes were sequenced from individu...

  15. Transport of Ions Across the Inner Envelope Membrane of Chloroplasts

    Energy Technology Data Exchange (ETDEWEB)

    McCarty, R. E.

    2004-06-02

    The technical report outlines the results of nine years of research on how ions cross the inner envelope membrane of chloroplasts. The ions include protons, nitrite, calcium and ferrous iron. Bicarbonate transport was also studied.

  16. Separation of Chloroplast Pigments Using Reverse Phase Chromatography.

    Science.gov (United States)

    Reese, R. Neil

    1997-01-01

    Presents a protocol that uses reverse phase chromatography for the separation of chloroplast pigments. Provides a simple and relatively safe procedure for use in teaching laboratories. Discusses pigment extraction, chromatography, results, and advantages of the process. (JRH)

  17. The complete chloroplast genome sequence of Zanthoxylum piperitum.

    Science.gov (United States)

    Lee, Jonghoon; Lee, Hyeon Ju; Kim, Kyunghee; Lee, Sang-Choon; Sung, Sang Hyun; Yang, Tae-Jin

    2016-09-01

    The complete chloroplast genome sequence of Zanthoxylum piperitum, a plant species with useful aromatic oils in family Rutaceae, was generated in this study by de novo assembly with whole-genome sequence data. The chloroplast genome was 158 154 bp in length with a typical quadripartite structure containing a pair of inverted repeats of 27 644 bp, separated by large single copy and small single copy of 85 340 bp and 17 526 bp, respectively. The chloroplast genome harbored 112 genes consisting of 78 protein-coding genes 30 tRNA genes and 4 rRNA genes. Phylogenetic analysis of the complete chloroplast genome sequences with those of known relatives revealed that Z. piperitum is most closely related to the Citrus species. PMID:26260183

  18. Sequence evidence for the symbiotic origins of chloroplasts and mitochondria

    Science.gov (United States)

    George, D. G.; Hunt, L. T.; Dayhoff, M. O.

    1983-01-01

    The origin of mitochondria and chloroplasts is investigated on the basis of prokaryotic and early-eukaryotic evolutionary trees derived from protein and nucleic-acid sequences by the method of Dayhoff (1979). Trees for bacterial ferrodoxins, 5S ribosomal RNA, c-type cytochromes, the lipid-binding subunit of ATPase, and dihydrofolate reductase are presented and discussed. Good agreement among the trees is found, and it is argued that the mitochondria and chloroplasts evolved by multiple symbiotic events.

  19. Copper Delivery to Chloroplast Proteins and its Regulation

    OpenAIRE

    Aguirre, Guadalupe; Pilon, Marinus

    2016-01-01

    Copper is required for photosynthesis in chloroplasts of plants because it is a cofactor of plastocyanin, an essential electron carrier in the thylakoid lumen. Other chloroplast copper proteins are copper/zinc superoxide dismutase and polyphenol oxidase, but these proteins seem to be dispensable under conditions of low copper supply when transcripts for these proteins undergo microRNA-mediated down regulation. Two ATP-driven copper transporters function in tandem to deliver copper to chloropl...

  20. A rapid, modular and marker-free chloroplast expression system for the green alga Chlamydomonas reinhardtii.

    Science.gov (United States)

    Bertalan, Ivo; Munder, Matthias C; Weiß, Caroline; Kopf, Judith; Fischer, Dirk; Johanningmeier, Udo

    2015-02-10

    In search of alternative expression platforms heterologous protein production in microalgae has gained increasing importance in the last years. Particularly, the chloroplast of the green alga Chlamydomonas reinhardtii has been adopted to successfully express foreign proteins like vaccines and antibodies. However, when compared with other expression systems, the development of the algal chloroplast to a powerful production platform for recombinant proteins is still in its early stages. In an effort to further improve methods for a reliable and rapid generation of transplastomic Chlamydomonas strains we constructed the key plasmid pMM2 containing the psbA gene and a multiple cloning site for foreign gene insertion. The psbA gene allows a marker-free selection procedure using as a recipient the Fud7 strain of Chlamydomonas, which grows on media containing acetate as a carbon source, but is unable to grow photoautotrophically due to the lack of an intact psbA gene. Biolistic transformation of Fud7 with vectors containing this gene restores photoautotrophic growth and thus permits selection in the light on media without carbon sources and antibiotics. The multiple cloning site with a BsaI recognition sequence allows type IIs restriction enzyme-based modular cloning which rapidly generates new gene constructs without sequences, which could influence the expression and characteristics of the foreign protein. In order to demonstrate the feasibility of this approach, a codon optimized version of the gene for the bacterial protein MPT64 has been integrated into the plastome. Several strains with different promoter/UTR combinations show a stable expression of the HA tagged MPT64 protein in Chlamydomonas chloroplasts. PMID:25554634

  1. Inhibition of chloroplast protein synthesis following light chilling of tomato

    International Nuclear Information System (INIS)

    In the present study we looked at the effects of a high light chill on the pulsed incorporation of 35S methionine into total, stromal, and thylakoid proteins of lightly abraded leaflets of 18-21 day old tomato (Lycopersicon esculentum Mill ca. Floramerica) seedlings. Based on gel fluorographic patterns of marker proteins that are indicative of the net rates of chloroplast and cytoplasmic protein synthesis, there appears to be a nearly complete cessation of chloroplastic protein synthesis. No labeling is observed for either the stromal large subunit of Rubisco or the thylakoid-bound alpha and beta subunits of the coupling factor. One notable exception, however, appears to be the 32 kd, D1 protein. Its net synthetic rate remains high despite the inhibition of other chloroplastically synthesized proteins. The small subunit of Rubicso, LHCP-II, as well as several other proteins of known cytoplasmic origin, were still synthesized, albeit, at lower than control rates. Light chilling of chill-insensitive spinach produced a similar, but less dramatic differential behavior between chloroplastic and cytoplasmic protein synthesis. It appears, in chilling-sensitive plants, that chloroplast protein synthesis exhibits a greater sensitivity to low temperature inhibition than does cytoplasmic protein synthesis and that recovery of chloroplast protein synthesis may play an important role in recovery of photosynthetic activity following chilling

  2. Role of mitochondria in sulfolipid biosynthesis by Euglena chloroplasts

    International Nuclear Information System (INIS)

    Sulfate activation occurs in Euglena mitochondria the authors now find that the sulfate activating enzymes are absent from Euglena chloroplasts. Cells of mutant W10BSmL lacking plastids also lack detectable sulfolipid (SL) when grown on 35SO42- indicating that SL is absent from the mitochondria and is exclusively in the plastids. Plastids alone will convert 35S-cysteine to 35SL in the presence of ATP and Mg2+; light is stimulatory. Under similar conditions, chloroplasts and mitochondria incubated together convert 35SO42- to plastid-localized 35SL but either organelle incubated alone fails to effect this conversion. Unlabeled cysteine blocks SL labeling from sulfate in the mixed incubation; since cysteine is formed from sulfate by Euglena mitochrondria, cysteine (and other compounds) may move from the mitochondrion to the chloroplast to provide the sulfo group for SL formation. Although mitochondria form labeled protein from 35SO42- via cysteine, chloroplasts alone do not form labeled protein from 35SO42-, ATP and Mg2+ in light or darkness; incubation of chloroplasts plus mitochondria under these conditions labels chloroplast protein

  3. Expression of human soluble TRAIL in Chlamydomonas reinhardtii chloroplast

    Institute of Scientific and Technical Information of China (English)

    YANG Zongqi; LI yinü; CHEN Feng; LI Dong; ZHANG Zhifang; LIU Yanxin; ZHENG Dexian; WANG Yong; SHEN Guifang

    2006-01-01

    Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induces selectively apoptosis in various tumor cells and virus-infected cells, but rarely in normal cells. A chloroplast expression vector, p64TRAIL, containing the cDNA coding for the soluble TRAIL (sTRAIL), was constructed with clpP-trnL-petB-chlL-rpl23-rpl2 as Chlamydomonas reinhardtii plastid homologous recombinant fragments and spectinomycin-resistant aadA gene as a select marker. The plasmid p64TRAIL was transferred into the chloroplast genome of C. reinhardtii by the biolistic method. Three independently transformed lines were obtained by 100 mg/L spectinomycin selection. PCR amplification, Southern blot analysis of the sTRAIL coding region DNA and cultivation cells in the dark all showed that the exogenous DNA had been integrated into chloroplast genome of C. reinhardtii. Western blot analysis showed that human soluble TRAIL was expressed in C. reinhardtii chloroplast. The densitometric analysis of Western blot indicated that the expressed human sTRAIL protein in the chloroplasts of C. reinhardtii accounted for about 0.43%-0.67% of the total soluble proteins.These experimental results demonstrated the possibility of using transgenic chloroplasts of green alga as bioreactors for production of biopharmaceuticals.

  4. Reconstructing the ancestral germ line methylation state of young repeats.

    Science.gov (United States)

    Feuerbach, Lars; Lyngsø, Rune B; Lengauer, Thomas; Hein, Jotun

    2011-06-01

    One of the key objectives of comparative genomics is the characterization of the forces that shape genomes over the course of evolution. In the last decades, evidence has been accumulated that for vertebrate genomes also epigenetic modifications have to be considered in this context. Especially, the elevated mutation frequency of 5-methylcytosine (5mC) is assumed to facilitate the depletion of CpG dinucleotides in species that exhibit global DNA methylation. For instance, the underrepresentation of CpG dinucleotides in many mammalian genomes is attributed to this effect, which is only neutralized in so-called CpG islands (CGIs) that are preferentially unmethylated and thus partially protected from rapid CpG decay. For primate-specific CpG-rich transposable elements from the ALU family, it is unclear whether their elevated CpG frequency is caused by their small age or by the absence of DNA methylation. In consequence, these elements are often misclassified in CGI annotations. We present a method for the estimation of germ line methylation from pairwise ancestral-descendant alignments. The approach is validated in a simulation study and tested on DNA repeats from the AluSx family. We conclude that a predicted unmethylated state in the germ line is highly correlated with epigenetic activity of the respective genomic region. Thus, CpG-rich repeats can be facilitated as in silico probes for the epigenetic potential of their genomic neighborhood. PMID:21212152

  5. An ancestral HIV-2/simian immunodeficiency virus peptide with potent HIV-1 and HIV-2 fusion inhibitor activity

    OpenAIRE

    Borrego, Pedro; Calado, Rita; Marcelino, José M.; Pereira, Patrícia MR; Quintas, Alexandre; Barroso, Helena; Taveira, Nuno

    2013-01-01

    "Objectives: To produce new fusion inhibitor peptides for HIV-1 and HIV-2 based on ancestral envelope sequences. Methods: HIV-2/simian immunodeficiency virus (SIV) ancestral transmembrane protein sequences were reconstructed and ancestral peptides were derived from the helical region 2 (HR2). The activity of one ancestral peptide (named P3) was examined against a panel of HIV-1 and HIV-2 primary isolates in TZM-bl cells and peripheral blood mononuclear cells and compared to ...

  6. Biosynthesis of gold nanoparticles using chloroplasts

    Directory of Open Access Journals (Sweden)

    Zhang YX

    2011-11-01

    Full Text Available Yi Xia Zhang1, Jun Zheng2, Guo Gao1, Yi Fei Kong1, Xiao Zhi1, Kan Wang1, Xue Qing Zhang1, Da Xiang Cui11Department of Bio-Nano-Science and Engineering, National Key Laboratory of Nano/Micro Fabrication Technology, Key Laboratory for Thin Film and Microfabrication of Ministry of Education, Institute of Micro-Nano Science and Technology, Shanghai Jiao Tong University, Shanghai, 2Wheat Research Institute, Academy of Agricultural Sciences, Linfen, Shan Xi, People's Republic of ChinaAbstract: In this paper, a new method of one-pot biosynthesizing of gold nanoparticles (GNPs, using chloroplasts as reductants and stabilizers is reported. The as-prepared GNPs were characterized by ultraviolet visible spectroscopy, transmission electron microscopy, X-ray powder diffraction, and Fourier transform infrared spectroscopy (FTIR. The cytotoxicity of the GNPs was evaluated using the 3-(4,5-Dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT method against gastric mucous cell line GES-1 and gastric cancer cell line MGC-803. Rhodamine 6G as a Raman probe was used for investigating surface-enhanced Raman spectroscopy (SERS enhancement of GNPs. The transmission electron microscopy results indicated that the GNPs were spherical in structure and almost 20 nm in diameter. Ultraviolet visible spectroscopy exhibited an absorption peak at 545 nm. The GNPs exhibited high crystallinity, with the (111 plane as the predominant orientation, clarified by X-ray powder diffraction. In addition, a potential mechanism was proposed to interpret the formation process of GNPs, mainly based on the analysis of FTIR results. The FTIR spectrum confirmed that the GNPs were carried with N–H groups. Toxicological assays of as-prepared GNPs revealed that the green GNPs were nontoxic. SERS analysis revealed that the GNPs without any treatment could substantially enhance the Raman signals of rhodamine 6G. The Raman enhancement factor was calculated to be nearly 1010 orders of magnitude

  7. Photosynthetic assimilation of 14C in isolated chloroplasts in the presence of NO3-, SO4- and NH4+

    International Nuclear Information System (INIS)

    Quantitative changes in carbon photosynthesis assimilation occurring as an effect of varying nitrate, sulfate and ammonia ions in the incubation medium were studied in isolated chloroplasts of spinach. Carbon photosynthetic assimilation is enhanced under the influence of rising nitrate anion concentrations to a certain level. The percentage of 14C concent in the insoluble products is also raised while in glycolic acid it is reduced. The nitrate anion has an effect similar to that of the bicarbonic anion the same processes. Ammonium and sulfate ions have the opposite effect. It can be assumed that the established effect of the ions studied is due to the influence they have on photosynthetic phosphorylation. (author)

  8. Fatty acid synthesis by spinach chloroplasts, 3

    International Nuclear Information System (INIS)

    The modes of actions of photosynthetic inhibitors on photosynthesis and fatty acid synthesis were examined. DCMU, an electron transport inhibitor, inhibited fatty acid synthesis and photophosphorylation to the same extent, suggesting dependence of fatty acid synthesis on photosynthesis. The same was also the case with FCCP, a photophosphorylation uncoupler. In contrast, NH4Cl and phlorizin at concentrations completely suppressing ATP formation, only partially inhibited the fatty acid synthesis. These facts suggest that a certain level of high-energy intermediate (state) is responsible for the light enhancement of fatty acid synthesis. This idea is further supported by the fact that the partial inhibition of fatty acid synthesis by NH4Cl was relieved by addition of DCCD at low concentrations suppressing the ATP formation but not completely destroying the high energy intermediate. The lag period in the initial period of fatty acid synthesis was shortened by preillumination of chloroplasts, even in the absence of ADP. This indicates that the light dependent fatty acid synthesis is closely associated with the high-energy intermediate (state), but not directly with ATP formation by photophosphorylation. (author)

  9. Nitrogen control of chloroplast differentiation. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, G.W.

    1998-05-01

    This project was directed toward understanding at the physiological, biochemical and molecular levels of how photosynthetic organisms adapt to long-term nitrogen-deficiency conditions is quite incomplete even though limitation of this nutrient is the most commonly restricts plant growth and development. For our work on this problem, the unicellular green alga, Chlamydomonas reinhardtii, was grown in continuous cultures in which steady-state levels of nitrogen can be precisely controlled. N-limited cells exhibit the classical symptoms of deficiency of this nutrient, chlorosis and slow growth rates, and respond to nitrogen provision by rapid greening and chloroplast differentiation. We have addressed three aspects of this problem: (1) the regulation of pigment synthesis; (2) control of expression of nuclear genes encoding photosynthetic proteins; (3) changes in metabolic and electron transport pathways that enable sustained CO{sub 2} fixation even though they cannot be readily converted into amino and nucleic acids. For the last, principle components are: (a) enhanced mitochondrial respiratory activity intimately associated with photosynthates, and (b) the occurrence in thylakoids of a supplemental electron transport pathway that facilitates reduction of the plastoquinone pool. Together, these distinguishing features of N-limited cells are likely to enable cell survival, especially under conditions of high irradiance stress.

  10. Genome-wide inference of ancestral recombination graphs.

    Science.gov (United States)

    Rasmussen, Matthew D; Hubisz, Melissa J; Gronau, Ilan; Siepel, Adam

    2014-01-01

    The complex correlation structure of a collection of orthologous DNA sequences is uniquely captured by the "ancestral recombination graph" (ARG), a complete record of coalescence and recombination events in the history of the sample. However, existing methods for ARG inference are computationally intensive, highly approximate, or limited to small numbers of sequences, and, as a consequence, explicit ARG inference is rarely used in applied population genomics. Here, we introduce a new algorithm for ARG inference that is efficient enough to apply to dozens of complete mammalian genomes. The key idea of our approach is to sample an ARG of [Formula: see text] chromosomes conditional on an ARG of [Formula: see text] chromosomes, an operation we call "threading." Using techniques based on hidden Markov models, we can perform this threading operation exactly, up to the assumptions of the sequentially Markov coalescent and a discretization of time. An extension allows for threading of subtrees instead of individual sequences. Repeated application of these threading operations results in highly efficient Markov chain Monte Carlo samplers for ARGs. We have implemented these methods in a computer program called ARGweaver. Experiments with simulated data indicate that ARGweaver converges rapidly to the posterior distribution over ARGs and is effective in recovering various features of the ARG for dozens of sequences generated under realistic parameters for human populations. In applications of ARGweaver to 54 human genome sequences from Complete Genomics, we find clear signatures of natural selection, including regions of unusually ancient ancestry associated with balancing selection and reductions in allele age in sites under directional selection. The patterns we observe near protein-coding genes are consistent with a primary influence from background selection rather than hitchhiking, although we cannot rule out a contribution from recurrent selective sweeps. PMID:24831947

  11. Genome-wide inference of ancestral recombination graphs.

    Directory of Open Access Journals (Sweden)

    Matthew D Rasmussen

    Full Text Available The complex correlation structure of a collection of orthologous DNA sequences is uniquely captured by the "ancestral recombination graph" (ARG, a complete record of coalescence and recombination events in the history of the sample. However, existing methods for ARG inference are computationally intensive, highly approximate, or limited to small numbers of sequences, and, as a consequence, explicit ARG inference is rarely used in applied population genomics. Here, we introduce a new algorithm for ARG inference that is efficient enough to apply to dozens of complete mammalian genomes. The key idea of our approach is to sample an ARG of [Formula: see text] chromosomes conditional on an ARG of [Formula: see text] chromosomes, an operation we call "threading." Using techniques based on hidden Markov models, we can perform this threading operation exactly, up to the assumptions of the sequentially Markov coalescent and a discretization of time. An extension allows for threading of subtrees instead of individual sequences. Repeated application of these threading operations results in highly efficient Markov chain Monte Carlo samplers for ARGs. We have implemented these methods in a computer program called ARGweaver. Experiments with simulated data indicate that ARGweaver converges rapidly to the posterior distribution over ARGs and is effective in recovering various features of the ARG for dozens of sequences generated under realistic parameters for human populations. In applications of ARGweaver to 54 human genome sequences from Complete Genomics, we find clear signatures of natural selection, including regions of unusually ancient ancestry associated with balancing selection and reductions in allele age in sites under directional selection. The patterns we observe near protein-coding genes are consistent with a primary influence from background selection rather than hitchhiking, although we cannot rule out a contribution from recurrent selective

  12. Ancestral Genomes, Sex, and the Population Structure of Trypanosoma cruzi.

    Directory of Open Access Journals (Sweden)

    2006-03-01

    Full Text Available Acquisition of detailed knowledge of the structure and evolution of Trypanosoma cruzi populations is essential for control of Chagas disease. We profiled 75 strains of the parasite with five nuclear microsatellite loci, 24Salpha RNA genes, and sequence polymorphisms in the mitochondrial cytochrome oxidase subunit II gene. We also used sequences available in GenBank for the mitochondrial genes cytochrome B and NADH dehydrogenase subunit 1. A multidimensional scaling plot (MDS based in microsatellite data divided the parasites into four clusters corresponding to T. cruzi I (MDS-cluster A, T. cruzi II (MDS-cluster C, a third group of T. cruzi strains (MDS-cluster B, and hybrid strains (MDS-cluster BH. The first two clusters matched respectively mitochondrial clades A and C, while the other two belonged to mitochondrial clade B. The 24Salpha rDNA and microsatellite profiling data were combined into multilocus genotypes that were analyzed by the haplotype reconstruction program PHASE. We identified 141 haplotypes that were clearly distributed into three haplogroups (X, Y, and Z. All strains belonging to T. cruzi I (MDS-cluster A were Z/Z, the T. cruzi II strains (MDS-cluster C were Y/Y, and those belonging to MDS-cluster B (unclassified T. cruzi had X/X haplogroup genotypes. The strains grouped in the MDS-cluster BH were X/Y, confirming their hybrid character. Based on these results we propose the following minimal scenario for T. cruzi evolution. In a distant past there were at a minimum three ancestral lineages that we may call, respectively, T. cruzi I, T. cruzi II, and T. cruzi III. At least two hybridization events involving T. cruzi II and T. cruzi III produced evolutionarily viable progeny. In both events, the mitochondrial recipient (as identified by the mitochondrial clade of the hybrid strains was T. cruzi II and the mitochondrial donor was T. cruzi III.

  13. The Korarchaeota: Archaeal orphans representing an ancestral lineage of life

    Energy Technology Data Exchange (ETDEWEB)

    Elkins, James G.; Kunin, Victor; Anderson, Iain; Barry, Kerrie; Goltsman, Eugene; Lapidus, Alla; Hedlund, Brian; Hugenholtz, Phil; Kyrpides, Nikos; Graham, David; Keller, Martin; Wanner, Gerhard; Richardson, Paul; Stetter, Karl O.

    2007-05-01

    Based on conserved cellular properties, all life on Earth can be grouped into different phyla which belong to the primary domains Bacteria, Archaea, and Eukarya. However, tracing back their evolutionary relationships has been impeded by horizontal gene transfer and gene loss. Within the Archaea, the kingdoms Crenarchaeota and Euryarchaeota exhibit a profound divergence. In order to elucidate the evolution of these two major kingdoms, representatives of more deeply diverged lineages would be required. Based on their environmental small subunit ribosomal (ss RNA) sequences, the Korarchaeota had been originally suggested to have an ancestral relationship to all known Archaea although this assessment has been refuted. Here we describe the cultivation and initial characterization of the first member of the Korarchaeota, highly unusual, ultrathin filamentous cells about 0.16 {micro}m in diameter. A complete genome sequence obtained from enrichment cultures revealed an unprecedented combination of signature genes which were thought to be characteristic of either the Crenarchaeota, Euryarchaeota, or Eukarya. Cell division appears to be mediated through a FtsZ-dependent mechanism which is highly conserved throughout the Bacteria and Euryarchaeota. An rpb8 subunit of the DNA-dependent RNA polymerase was identified which is absent from other Archaea and has been described as a eukaryotic signature gene. In addition, the representative organism possesses a ribosome structure typical for members of the Crenarchaeota. Based on its gene complement, this lineage likely diverged near the separation of the two major kingdoms of Archaea. Further investigations of these unique organisms may shed additional light onto the evolution of extant life.

  14. β-Propeller blades as ancestral peptides in protein evolution.

    Directory of Open Access Journals (Sweden)

    Klaus O Kopec

    Full Text Available Proteins of the β-propeller fold are ubiquitous in nature and widely used as structural scaffolds for ligand binding and enzymatic activity. This fold comprises between four and twelve four-stranded β-meanders, the so called blades that are arranged circularly around a central funnel-shaped pore. Despite the large size range of β-propellers, their blades frequently show sequence similarity indicative of a common ancestry and it has been proposed that the majority of β-propellers arose divergently by amplification and diversification of an ancestral blade. Given the structural versatility of β-propellers and the hypothesis that the first folded proteins evolved from a simpler set of peptides, we investigated whether this blade may have given rise to other folds as well. Using sequence comparisons, we identified proteins of four other folds as potential homologs of β-propellers: the luminal domain of inositol-requiring enzyme 1 (IRE1-LD, type II β-prisms, β-pinwheels, and WW domains. Because, with increasing evolutionary distance and decreasing sequence length, the statistical significance of sequence comparisons becomes progressively harder to distinguish from the background of convergent similarities, we complemented our analyses with a new method that evaluates possible homology based on the correlation between sequence and structure similarity. Our results indicate a homologous relationship of IRE1-LD and type II β-prisms with β-propellers, and an analogous one for β-pinwheels and WW domains. Whereas IRE1-LD most likely originated by fold-changing mutations from a fully formed PQQ motif β-propeller, type II β-prisms originated by amplification and differentiation of a single blade, possibly also of the PQQ type. We conclude that both β-propellers and type II β-prisms arose by independent amplification of a blade-sized fragment, which represents a remnant of an ancient peptide world.

  15. β-Propeller Blades as Ancestral Peptides in Protein Evolution

    Science.gov (United States)

    Kopec, Klaus O.; Lupas, Andrei N.

    2013-01-01

    Proteins of the β-propeller fold are ubiquitous in nature and widely used as structural scaffolds for ligand binding and enzymatic activity. This fold comprises between four and twelve four-stranded β-meanders, the so called blades that are arranged circularly around a central funnel-shaped pore. Despite the large size range of β-propellers, their blades frequently show sequence similarity indicative of a common ancestry and it has been proposed that the majority of β-propellers arose divergently by amplification and diversification of an ancestral blade. Given the structural versatility of β-propellers and the hypothesis that the first folded proteins evolved from a simpler set of peptides, we investigated whether this blade may have given rise to other folds as well. Using sequence comparisons, we identified proteins of four other folds as potential homologs of β-propellers: the luminal domain of inositol-requiring enzyme 1 (IRE1-LD), type II β-prisms, β-pinwheels, and WW domains. Because, with increasing evolutionary distance and decreasing sequence length, the statistical significance of sequence comparisons becomes progressively harder to distinguish from the background of convergent similarities, we complemented our analyses with a new method that evaluates possible homology based on the correlation between sequence and structure similarity. Our results indicate a homologous relationship of IRE1-LD and type II β-prisms with β-propellers, and an analogous one for β-pinwheels and WW domains. Whereas IRE1-LD most likely originated by fold-changing mutations from a fully formed PQQ motif β-propeller, type II β-prisms originated by amplification and differentiation of a single blade, possibly also of the PQQ type. We conclude that both β-propellers and type II β-prisms arose by independent amplification of a blade-sized fragment, which represents a remnant of an ancient peptide world. PMID:24143202

  16. Glucose respiration in the intact chloroplast of Chlamydomonas reinhardtii

    International Nuclear Information System (INIS)

    Chloroplastic respiration was monitored by measuring 14CO2 from 14C glucose in the darkened Chlamydomonas reinhardtii F-60 chloroplast, The patterns of 14CO2 evolution from labeled glucose in the absence and presence of the inhibitors iodoacetamide, glycolate-2-phosphate, and phosphoenolypyruvate were those expected from the oxidative pentose phosphate cycle and glycolysis. The Km for glucose was 56 micromolar and for MgATP was 200 micromolar. Release of 14CO2 was inhibited by phloretin and inorganic phosphate. Comparing the inhibition of CO2 evolution generated by pH 7.5 with respect to pH 8.2 (optimum) in chloroplasts given C-1, C-2, and C-6 labeled glucose indicated that a suboptimum pH affects the recycling of the pentose phosphate intermediates to a greater extent than CO2 evolution from C-1 of glucose. Respiratory inhibition by pH 7.5 in the darkened chloroplast was alleviated by NH4Cl and KCl (stromal alkalating agents), iodoacetamide (an inhibitor of glyceraldehyde 3-phosphate dehydrogenase), or phosphoenolypyruvate (an inhibitor of phosphofructokinase). It is concluded that the site which primarily mediates respiration in the darkened Chlamydomonas chloroplast is the fructose-1,6-bisphosphatase/phosphofructokinase junction. The respiratory pathways described here can account for the total oxidation of a hexose to Co2 and for interactions between carbohydrate metabolism and the oxyhydrogen reaction in algal cells adapted to a hydrogen metabolism

  17. Arabidopsis chloroplast chaperonin 10 is a calmodulin-binding protein

    Science.gov (United States)

    Yang, T.; Poovaiah, B. W.

    2000-01-01

    Calcium regulates diverse cellular activities in plants through the action of calmodulin (CaM). By using (35)S-labeled CaM to screen an Arabidopsis seedling cDNA expression library, a cDNA designated as AtCh-CPN10 (Arabidopsis thaliana chloroplast chaperonin 10) was cloned. Chloroplast CPN10, a nuclear-encoded protein, is a functional homolog of E. coli GroES. It is believed that CPN60 and CPN10 are involved in the assembly of Rubisco, a key enzyme involved in the photosynthetic pathway. Northern analysis revealed that AtCh-CPN10 is highly expressed in green tissues. The recombinant AtCh-CPN10 binds to CaM in a calcium-dependent manner. Deletion mutants revealed that there is only one CaM-binding site in the last 31 amino acids of the AtCh-CPN10 at the C-terminal end. The CaM-binding region in AtCh-CPN10 has higher homology to other chloroplast CPN10s in comparison to GroES and mitochondrial CPN10s, suggesting that CaM may only bind to chloroplast CPN10s. Furthermore, the results also suggest that the calcium/CaM messenger system is involved in regulating Rubisco assembly in the chloroplast, thereby influencing photosynthesis. Copyright 2000 Academic Press.

  18. Comparison of intraspecific, interspecific and intergeneric chloroplast diversity in Cycads.

    Science.gov (United States)

    Jiang, Guo-Feng; Hinsinger, Damien Daniel; Strijk, Joeri Sergej

    2016-01-01

    Cycads are among the most threatened plant species. Increasing the availability of genomic information by adding whole chloroplast data is a fundamental step in supporting phylogenetic studies and conservation efforts. Here, we assemble a dataset encompassing three taxonomic levels in cycads, including ten genera, three species in the genus Cycas and two individuals of C. debaoensis. Repeated sequences, SSRs and variations of the chloroplast were analyzed at the intraspecific, interspecific and intergeneric scale, and using our sequence data, we reconstruct a phylogenomic tree for cycads. The chloroplast was 162,094 bp in length, with 133 genes annotated, including 87 protein-coding, 37 tRNA and 8 rRNA genes. We found 7 repeated sequences and 39 SSRs. Seven loci showed promising levels of variations for application in DNA-barcoding. The chloroplast phylogeny confirmed the division of Cycadales in two suborders, each of them being monophyletic, revealing a contradiction with the current family circumscription and its evolution. Finally, 10 intraspecific SNPs were found. Our results showed that despite the extremely restricted distribution range of C. debaoensis, using complete chloroplast data is useful not only in intraspecific studies, but also to improve our understanding of cycad evolution and in defining conservation strategies for this emblematic group. PMID:27558458

  19. The complete chloroplast genome of Capsicum frutescens (Solanaceae)1

    Science.gov (United States)

    Shim, Donghwan; Raveendar, Sebastin; Lee, Jung-Ro; Lee, Gi-An; Ro, Na-Young; Jeon, Young-Ah; Cho, Gyu-Taek; Lee, Ho-Sun; Ma, Kyung-Ho; Chung, Jong-Wook

    2016-01-01

    Premise of the study: We report the complete sequence of the chloroplast genome of Capsicum frutescens (Solanaceae), a species of chili pepper. Methods and Results: Using an Illumina platform, we sequenced the chloroplast genome of C. frutescens. The total length of the genome is 156,817 bp, and the overall GC content is 37.7%. A pair of 25,792-bp inverted repeats is separated by small (17,853 bp) and large (87,380 bp) single-copy regions. The C. frutescens chloroplast genome encodes 132 unique genes, including 87 protein-coding genes, 37 transfer RNA (tRNA) genes, and eight ribosomal RNA (rRNA) genes. Of these, seven genes are duplicated in the inverted repeats and 12 genes contain one or two introns. Comparative analysis with the reference chloroplast genome revealed 125 simple sequence repeat motifs and 34 variants, mostly located in the noncoding regions. Conclusions: The complete chloroplast genome sequence of C. frutescens reported here is a valuable genetic resource for Capsicum species. PMID:27213127

  20. Analysis of the stone ancestral hall of Guo’s tomb on Xiaotang mountainin Han dynasty architectural features

    Institute of Scientific and Technical Information of China (English)

    刘国庆

    2014-01-01

    The stone ancestral hall of Guo’s tomb in Xiaotang mountain is the earliest existing buildings on the ground in China. It has a very high historical, cultural and artistic value, and it was described by the ancient and modern scholars and experts in their books and articles. But the study of architectural of ancestral hall was emphasized from 1930s, and became a brilliant star in the Chinese historic buildings. In this article, the architectural characteristics of the stone ancestral hall are discussed through fieldworks, in order to clarify the real architecture appearance of the ancestral hall and refer more informations for comprehensive study of Xiaotang stone ancestral hall.

  1. An ancestral role for the mitochondrial pyruvate carrier in glucose-stimulated insulin secretion

    Directory of Open Access Journals (Sweden)

    Kyle S. McCommis

    2016-08-01

    Conclusions: Altogether, these studies suggest that the MPC plays an important and ancestral role in insulin-secreting cells in mediating glucose sensing, regulating insulin secretion, and controlling systemic glycemia.

  2. Mapping ancestral genomes with massive gene loss: a matrix sandwich problem.

    OpenAIRE

    Gavranović, Haris; Chauve, Cedric; Salse, Jérôme; Tannier, Eric

    2011-01-01

    MOTIVATION: Ancestral genomes provide a better way to understand the structural evolution of genomes than the simple comparison of extant genomes. Most ancestral genome reconstruction methods rely on universal markers, that is, homologous families of DNA segments present in exactly one exemplar in every considered species. Complex histories of genes or other markers, undergoing duplications and losses, are rarely taken into account. It follows that some ancestors are inaccessible by these met...

  3. Molecular biology and physiology of isolated chloroplasts from the algae Vaucheria

    OpenAIRE

    Didriksen, Alena

    2010-01-01

    Sea slugs of the genus Elysia (e.g. E. chlorotica) are known for their ability to incorporate chloroplasts from the yellow-green alga Vaucheria litorea. These “kleptoplasts” stay active in the digestive tract of the sea slug for several months. Chloroplasts from Vaucheria litorea are also reported to be significantly more stable after in vitro isolation than chloroplasts of other algae or of higher plants. In organello assays with isolated chloroplasts are used in studies on photosynthetical ...

  4. Chloroplast degeneration and its inhibition by kinetin in detached leaves of Cichorium intybus L.

    OpenAIRE

    F. Młodzianowski; L. Młodzanowska

    2015-01-01

    In the chicory (Cichorium intybus L. var. sativum cv. Polanowicka) leaves two types of chloroplasts are present differing by their degree of osmiophility of the thylakoid inside. This type of differentiation of chloroplasts has so far been found only in several plant species. The process of chloroplast degeneration in darkness is described. In osmiophilic chloroplasts at certain stage of degeneration minutely layered giant grana were found. Kinetin markedly inhibited the process of chloroplas...

  5. Development of chloroplast genomic resources for Cynara.

    Science.gov (United States)

    Curci, Pasquale L; De Paola, Domenico; Sonnante, Gabriella

    2016-03-01

    In this study, new chloroplast (cp) resources were developed for the genus Cynara, using whole cp genomes from 20 genotypes, by means of high-throughput sequencing technologies. Our target species included seven globe artichokes, two cultivated cardoons, eight wild artichokes, and three other wild Cynara species (C. baetica, C. cornigera and C. syriaca). One complete cp genome was isolated using short reads from a whole-genome sequencing project, while the others were obtained by means of long-range PCR, for which primer pairs are provided here. A de novo assembly strategy combined with a reference-based assembly allowed us to reconstruct each cp genome. Comparative analyses among the newly sequenced genotypes and two additional Cynara cp genomes ('Brindisino' artichoke and C. humilis) retrieved from public databases revealed 126 parsimony informative characters and 258 singletons in Cynara, for a total of 384 variable characters. Thirty-nine SSR loci and 34 other INDEL events were detected. After data analysis, 37 primer pairs for SSR amplification were designed, and these molecular markers were subsequently validated in our Cynara genotypes. Phylogenetic analysis based on all cp variable characters provided the best resolution when compared to what was observed using only parsimony informative characters, or only short 'variable' cp regions. The evaluation of the molecular resources obtained from this study led us to support the 'super-barcode' theory and consider the total cp sequence of Cynara as a reliable and valuable molecular marker for exploring species diversity and examining variation below the species level. PMID:26354522

  6. Evolutionary divergence of chloroplast FAD synthetase proteins

    Directory of Open Access Journals (Sweden)

    Arilla-Luna Sonia

    2010-10-01

    Full Text Available Abstract Background Flavin adenine dinucleotide synthetases (FADSs - a group of bifunctional enzymes that carry out the dual functions of riboflavin phosphorylation to produce flavin mononucleotide (FMN and its subsequent adenylation to generate FAD in most prokaryotes - were studied in plants in terms of sequence, structure and evolutionary history. Results Using a variety of bioinformatics methods we have found that FADS enzymes localized to the chloroplasts, which we term as plant-like FADS proteins, are distributed across a variety of green plant lineages and constitute a divergent protein family clearly of cyanobacterial origin. The C-terminal module of these enzymes does not contain the typical riboflavin kinase active site sequence, while the N-terminal module is broadly conserved. These results agree with a previous work reported by Sandoval et al. in 2008. Furthermore, our observations and preliminary experimental results indicate that the C-terminus of plant-like FADS proteins may contain a catalytic activity, but different to that of their prokaryotic counterparts. In fact, homology models predict that plant-specific conserved residues constitute a distinct active site in the C-terminus. Conclusions A structure-based sequence alignment and an in-depth evolutionary survey of FADS proteins, thought to be crucial in plant metabolism, are reported, which will be essential for the correct annotation of plant genomes and further structural and functional studies. This work is a contribution to our understanding of the evolutionary history of plant-like FADS enzymes, which constitute a new family of FADS proteins whose C-terminal module might be involved in a distinct catalytic activity.

  7. Comparison of the chloroplast peroxidase system in the chlorophyte Chlamydomonas reinhardtii, the bryophyte Physcomitrella patens, the lycophyte Selaginella moellendorffii and the seed plant Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Baier Margarete

    2010-06-01

    Full Text Available Abstract Background Oxygenic photosynthesis is accompanied by the formation of reactive oxygen species (ROS, which damage proteins, lipids, DNA and finally limit plant yield. The enzymes of the chloroplast antioxidant system are exclusively nuclear encoded. During evolution, plastid and mitochondrial genes were post-endosymbiotically transferred to the nucleus, adapted for eukaryotic gene expression and post-translational protein targeting and supplemented with genes of eukaryotic origin. Results Here, the genomes of the green alga Chlamydomonas reinhardtii, the moss Physcomitrella patens, the lycophyte Selaginella moellendorffii and the seed plant Arabidopsis thaliana were screened for ORFs encoding chloroplast peroxidases. The identified genes were compared for their amino acid sequence similarities and gene structures. Stromal and thylakoid-bound ascorbate peroxidases (APx share common splice sites demonstrating that they evolved from a common ancestral gene. In contrast to most cormophytes, our results predict that chloroplast APx activity is restricted to the stroma in Chlamydomonas and to thylakoids in Physcomitrella. The moss gene is of retrotransposonal origin. The exon-intron-structures of 2CP genes differ between chlorophytes and streptophytes indicating an independent evolution. According to amino acid sequence characteristics only the A-isoform of Chlamydomonas 2CP may be functionally equivalent to streptophyte 2CP, while the weakly expressed B- and C-isoforms show chlorophyte specific surfaces and amino acid sequence characteristics. The amino acid sequences of chloroplast PrxII are widely conserved between the investigated species. In the analyzed streptophytes, the genes are unspliced, but accumulated four introns in Chlamydomonas. A conserved splice site indicates also a common origin of chlorobiont PrxQ. The similarity of splice sites also demonstrates that streptophyte glutathione peroxidases (GPx are of common origin. Besides

  8. Factors affecting the stability of chloroplast membranes in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Takaoki, T.; Torres-Pereira, J.; Packer, L.

    1974-01-01

    Factors which affect the stability of light-induced atebrin fluorescence quenching activity in chloroplast membranes, a measure of the electron transport dependent formation of energy-linked H/sup +/ gradients, were investigated in vitro. Class II spinach chloroplast membranes were isolated and stored at 0 to 4/sup 0/C and aliquots were subsequently tested for their retention of energizing capacity. The main factors which increase the stability of this activity were found to be (a) isolation in a potassium-containing medium but storage in a sucrose medium containing a low concentration of electrolytes; (b) the presence of butylated hydroxytoluene (an antioxidant), and a protein such as bovine serum albumin to remove free fatty acids in the medium during storage. Under these conditions, the energization capacity of chloroplasts is retained for more than 40 days.

  9. Identification of the 64 kilodalton chloroplast stromal phosphoprotein as phosphoglucomutase

    International Nuclear Information System (INIS)

    Phosphorylation of the 64 kilodalton stromal phosphoprotein by incubation of pea (Pisum sativum) chloroplast extracts with [γ-32P]ATP decreased in the presence of Glc-6-P and Glc-1,6-P2, but was stimulated by glucose. Two-dimensional gel electrophoresis following incubation of intact chloroplasts and stromal extracts with [γ-32P]ATP, or incubation of stromal extracts and partially purified phosphoglucomutase (EC 2.7.5.1) with [32P]Glc-1-P showed that the identical 64 kilodalton polypeptide was labeled. A 62 kilodalton polypeptide was phosphorylated by incubation of tobacco (Nicotiana sylvestris) stromal extracts with either [γ-32P]ATP or [32P]Glc-1-P. In contrast, an analogous polypeptide was not phosphorylated in extracts from a tobacco mutant deficient in plastid phosphoglucomutase activity. The results indicate that the 64 (or 62) kilodalton chloroplast stromal phosphoprotein is phosphoglucomutase

  10. The complete chloroplast genome sequence of Alocasia macrorrhizos.

    Science.gov (United States)

    Wang, Bin; Han, Limin

    2016-09-01

    The complete chloroplast sequence of Alocasia macrorrhizos is 154 995 bp in length, containing a pair of inverted repeats of 25 944 bp separated by a large single-copy (LSC) region and a small single-copy (SSC) region of 87 366 bp and 15 741 bp, respectively. The chloroplast genome encodes 132 predicted functional genes, including 87 protein-coding genes, four ribosomal RNA genes, and 37 transfer RNA genes, 18 of which are duplicated in the inverted repeat regions. In these genes, 16 genes contained single intron and two genes comprising double introns. A maximum-likelihood phylogenetic analysis using complete chloroplast genome revealed that A. macrorrhizos does not belong to Araceae family, which infers that the A. macrorrhizos is distant from the species in Araceae family. PMID:26258514

  11. IM30 triggers membrane fusion in cyanobacteria and chloroplasts.

    Science.gov (United States)

    Hennig, Raoul; Heidrich, Jennifer; Saur, Michael; Schmüser, Lars; Roeters, Steven J; Hellmann, Nadja; Woutersen, Sander; Bonn, Mischa; Weidner, Tobias; Markl, Jürgen; Schneider, Dirk

    2015-01-01

    The thylakoid membrane of chloroplasts and cyanobacteria is a unique internal membrane system harbouring the complexes of the photosynthetic electron transfer chain. Despite their apparent importance, little is known about the biogenesis and maintenance of thylakoid membranes. Although membrane fusion events are essential for the formation of thylakoid membranes, proteins involved in membrane fusion have yet to be identified in photosynthetic cells or organelles. Here we show that IM30, a conserved chloroplast and cyanobacterial protein of approximately 30 kDa binds as an oligomeric ring in a well-defined geometry specifically to membranes containing anionic lipids. Triggered by Mg(2+), membrane binding causes destabilization and eventually results in membrane fusion. We propose that IM30 establishes contacts between internal membrane sites and promotes fusion to enable regulated exchange of proteins and/or lipids in cyanobacteria and chloroplasts. PMID:25952141

  12. Transcriptome analysis of ectopic chloroplast development in green curd cauliflower (Brassica oleracea L. var. botrytis)

    Science.gov (United States)

    Chloroplasts are the green plastids where photosynthesis takes place. The biogenesis of chloroplasts requires the coordinate expression of both nuclear and chloroplast genes and is regulated by developmental and environmental signals. Despite extensive studies of this process, the genetic basis and ...

  13. Manipulating the chloroplast genome of Chlamydomonas: Present realities and future prospects

    Energy Technology Data Exchange (ETDEWEB)

    Boynton, J.; Gillham, N.; Hauser, C.; Heifetz, P.; Lers, A.; Newman, S.; Osmond, B.

    1992-12-31

    Biotechnology is being applied in vitro modification and stable reintroduction of chloroplast genes in Chlamydomonas reinhardtii and Nicotiana tabacum by homologous recombination. We are attempting the function analyses of plastid encoded proteins involved in photosynthesis, characterization of sequences which regulate expression of plastid genes at the transcriptional and translational levels, targeted disruption of chloroplast genes and molecular analysis of processes involved in chloroplast recombination.

  14. Salinity induces membrane structure and lipid changes in maize mesophyll and bundle sheath chloroplasts.

    Science.gov (United States)

    Omoto, Eiji; Iwasaki, Yugo; Miyake, Hiroshi; Taniguchi, Mitsutaka

    2016-05-01

    The membranes of Zea mays (maize) mesophyll cell (MC) chloroplasts are more vulnerable to salinity stress than are those of bundle sheath cell (BSC) chloroplasts. To clarify the mechanism underlying this difference in salt sensitivity, we monitored changes in the glycerolipid and fatty acid compositions of both types of chloroplast upon exposure to salinity stress. The monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG) contents were higher in MC chloroplasts than in BSC chloroplasts, in both the presence and absence of salt treatment. Under salt conditions, the MGDG level in MC chloroplasts was significantly lower than under normal conditions, while it was unchanged in BSC chloroplasts. In both types of chloroplast, the contents of DGDG, phosphatidylglycerol and phosphatidylinositol remained at the same levels in control and salt-treated plants, whereas sulfoquinovosyldiacylglycerol and phosphatidylcholine were significantly lower and higher, respectively, upon salt treatment. In addition, the fatty acid composition and double bond index of individual lipid classes were changed by salt treatment in both BSC and MC chloroplasts, although these factors had no effect on glycerolipid content. These findings suggest that the difference in salt sensitivity of MC and BSC chloroplast membranes is related to differences in MGDG responses to salinity. Thus, we propose that the low MGDG content and the low sensitivity of MGDG to salinity in BSC chloroplasts render them more tolerant than MC chloroplasts to salinity stress. PMID:26555406

  15. Chloroplast Iron Transport Proteins - Function and Impact on Plant Physiology.

    Science.gov (United States)

    López-Millán, Ana F; Duy, Daniela; Philippar, Katrin

    2016-01-01

    Chloroplasts originated about three billion years ago by endosymbiosis of an ancestor of today's cyanobacteria with a mitochondria-containing host cell. During evolution chloroplasts of higher plants established as the site for photosynthesis and thus became the basis for all life dependent on oxygen and carbohydrate supply. To fulfill this task, plastid organelles are loaded with the transition metals iron, copper, and manganese, which due to their redox properties are essential for photosynthetic electron transport. In consequence, chloroplasts for example represent the iron-richest system in plant cells. However, improvement of oxygenic photosynthesis in turn required adaptation of metal transport and homeostasis since metal-catalyzed generation of reactive oxygen species (ROS) causes oxidative damage. This is most acute in chloroplasts, where radicals and transition metals are side by side and ROS-production is a usual feature of photosynthetic electron transport. Thus, on the one hand when bound by proteins, chloroplast-intrinsic metals are a prerequisite for photoautotrophic life, but on the other hand become toxic when present in their highly reactive, radical generating, free ionic forms. In consequence, transport, storage and cofactor-assembly of metal ions in plastids have to be tightly controlled and are crucial throughout plant growth and development. In the recent years, proteins for iron transport have been isolated from chloroplast envelope membranes. Here, we discuss their putative functions and impact on cellular metal homeostasis as well as photosynthetic performance and plant metabolism. We further consider the potential of proteomic analyses to identify new players in the field. PMID:27014281

  16. Activation of a chloroplast type of fructose bisphosphatase from Chlamydomonas reinhardtii by light-mediated agents

    Science.gov (United States)

    Huppe, H. C.; Buchanan, B. B.

    1989-01-01

    A chloroplast type of fructose-1,6-bisphosphatase, a central regulatory enzyme of photosynthetic carbon metabolism, has been partially purified from Chlamydomonas reinhardtii. Unlike its counterpart from spinach chloroplasts, the algal FBPase showed a strict requirement for a dithiol reductant irrespective of Mg2+ concentration. The enzymes from the two sources resembled each other immunologically, in subunit molecular mass and response to pH. In the presence of dithiothreitol, the pH optimum for both the algal and spinach enzymes shifted from 8.5 to a more physiologic value of 8.0 as the Mg2+ concentration was increased from 1 to 16 mM. At 1 mM Mg2+, a concentration estimated to be close to physiological, the Chlamydomonas FBPase was active only in the presence of reduced thioredoxin and was most active with Chlamydomonas thioredoxin f. Under these conditions, the enzyme showed a pH optimum of 8.0. The data suggest that the Chlamydomonas enzyme resembles its spinach counterpart in most respects, but it has a stricter requirement for reduction and less strict reductant specificity. A comparison of the properties of the FBPases from Chlamydomonas and spinach will be helpful for elucidating the mechanism of the reductive activation of this enzyme.

  17. The action spectrum in chloroplast translocation in multilayer leaf cells

    Directory of Open Access Journals (Sweden)

    Zbigniew Lechowski

    2015-05-01

    Full Text Available By measurement of light transmittance through a leaf as criterion of chloroplast translocation, the action spectrum of Ajuga reptans was established. In the spectrum obtained, a correction was introduced for leaf autoabsorption calculated on the basis of the Beer-Lambert law. The action spectrum has two maxima: at λ= 375 nm and λ= 481 nm. The range above 502 nm has no significant effect on chloroplast translocation. Comparison with other objects examined demonstrated that in multilayer leaf cells riboflavin seems also to be a photoreceptor active in this process.

  18. Robust expression of a bioactive mammalian protein in chlamydomonas chloroplast

    Science.gov (United States)

    Mayfield, Stephen P.

    2010-03-16

    Methods and compositions are disclosed to engineer chloroplast comprising heterologous mammalian genes via a direct replacement of chloroplast Photosystem II (PSII) reaction center protein coding regions to achieve expression of recombinant protein above 5% of total protein. When algae is used, algal expressed protein is produced predominantly as a soluble protein where the functional activity of the peptide is intact. As the host algae is edible, production of biologics in this organism for oral delivery or proteins/peptides, especially gut active proteins, without purification is disclosed.

  19. Robust expression of a bioactive mammalian protein in Chlamydomonas chloroplast

    Energy Technology Data Exchange (ETDEWEB)

    Mayfield, Stephen P

    2015-01-13

    Methods and compositions are disclosed to engineer chloroplast comprising heterologous mammalian genes via a direct replacement of chloroplast Photosystem II (PSII) reaction center protein coding regions to achieve expression of recombinant protein above 5% of total protein. When algae is used, algal expressed protein is produced predominantly as a soluble protein where the functional activity of the peptide is intact. As the host algae is edible, production of biologics in this organism for oral delivery of proteins/peptides, especially gut active proteins, without purification is disclosed.

  20. The complete chloroplast genome of Schrenkiella parvula (Brassicaceae).

    Science.gov (United States)

    He, Qi; Hao, Guoqian; Wang, Xiaojuan; Bi, Hao; Li, Yuanshuo; Guo, Xinyi; Ma, Tao

    2016-09-01

    Schrenkiella parvula is an Arabidopsis-related model species used here for studying plant stress tolerance. In this study, the complete chloroplast genome sequence of S. parvula has been reported for the first time. The total length of the chloroplast genome was 153 979 bp, which had a typical quadripartite structure. The annotated plastid genome includes 87 protein-coding genes, 39 tRNA genes and 8 ribosomal RNA genes. The evolutionary relationships revealed by our phylogenetic analysis indicated that S. parvula is closer to the Brassiceae species when compared with Eutrema salsugineum. PMID:26260181

  1. Nucleotide sequence of a spinach chloroplast valine tRNA.

    OpenAIRE

    Sprouse, H M; Kashdan, M; Otis, L; Dudock, B

    1981-01-01

    The nucleotide sequence of a spinach chloroplast valine tRNA (sp. chl. tRNA Val) has been determined. This tRNA shows essentially equal homology to prokaryotic valine tRNAs (58-65% homology) and to the mitochondrial valine tRNAs of lower eukaryotes (yeast and N. crassa, 61-62% homology). Sp. chl. tRNA Val shows distinctly lower homology to mouse mitochondrial valine tRNA (53% homology) and to eukaryotic cytoplasmic valine tRNAs (47-53% homology). Sp. chl. tRNA Val, like all other chloroplast ...

  2. Characterization of elemental sulfur in isolated intact spinach chloroplasts

    International Nuclear Information System (INIS)

    Incubation of intact spinach (Spinacia oleracea L.) chloroplasts in the presence of 35SO42- resulted in the light-dependent formation of a chloroform-soluble sulfur-containing compound distinct from sulfolipid. The authors have identified this compound as the most stable form (S8) of elemental sulfur (S0, valence state for S = O) by mass spectrometry. It is possible that elemental sulfur (S0) was formed by oxidation of bound sulfide, i.e. after the photoreduction of sulfate to sulfide by intact chloroplasts, and released as S8 under the experimental conditions used for analysis

  3. Chloroplast degeneration and its inhibition by kinetin in detached leaves of Cichorium intybus L.

    Directory of Open Access Journals (Sweden)

    F. Młodzianowski

    2015-05-01

    Full Text Available In the chicory (Cichorium intybus L. var. sativum cv. Polanowicka leaves two types of chloroplasts are present differing by their degree of osmiophility of the thylakoid inside. This type of differentiation of chloroplasts has so far been found only in several plant species. The process of chloroplast degeneration in darkness is described. In osmiophilic chloroplasts at certain stage of degeneration minutely layered giant grana were found. Kinetin markedly inhibited the process of chloroplast degeneration, and after prolonged treatment even stimulated the stacking. process of grana thylakoids.

  4. Isolation of dimorphic chloroplasts from the single-cell C4 species Bienertia sinuspersici

    Directory of Open Access Journals (Sweden)

    Lung Shiu-Cheung

    2012-03-01

    Full Text Available Abstract Three terrestrial plants are known to perform C4 photosynthesis without the dual-cell system by partitioning two distinct types of chloroplasts in separate cytoplasmic compartments. We report herein a protocol for isolating the dimorphic chloroplasts from Bienertia sinuspersici. Hypo-osmotically lysed protoplasts under our defined conditions released intact compartments containing the central chloroplasts and intact vacuoles with adhering peripheral chloroplasts. Following Percoll step gradient purification both chloroplast preparations demonstrated high homogeneities as evaluated from the relative abundance of respective protein markers. This protocol will open novel research directions toward understanding the mechanism of single-cell C4 photosynthesis.

  5. Chloroplast genetics of chlamydomonas. I. Allelic segregation ratios

    International Nuclear Information System (INIS)

    This paper presents allelic segregation data from a series of 16 crosses segregated for nuclear and chloroplast genes. By means of pedigree analysis, segregants of chloroplast genes. By means of pedigree analysis, segregants of chloroplast markers occurring in the zygote have been distinguished from those occurring in zoospore clones. The genes ac1, ac2, and tm1 showed little if any deviation from 1:1 either in zygotic segregation or in zoospore clones. The genes sm2, ery, and spc showed a significant excess of the allele from the mt+ parent in zygotes. However, in zoospores, mt+ excess was seen only when the allele was the mutant (resistant) form but not when it was wild type (sensitive). These results show that the extent of preferential segregation differs in zygotes and in zoospores, and that preferential segregation is influenced by map location and by allele specificity. A comparison of progeny from zygotes mated after 0, 15'', 30'', and 50'' uv irradiation of the mt+ gametes demonstrated the lack of an effect of uv upon allelic segregation ratios. In total, these results exclude the multi-copy model of chloroplast genome segregation suggested by Gillham. Boynton and Lee (1974) and support the diploid model we have previously proposed

  6. Chloroplast genetics of chlamydomonas. I. Allelic segregation ratios. [UV radiation

    Energy Technology Data Exchange (ETDEWEB)

    Sager, R.; Ramanis, Z.

    1976-06-01

    This paper presents allelic segregation data from a series of 16 crosses segregated for nuclear and chloroplast genes. By means of pedigree analysis, segregants of chloroplast genes. By means of pedigree analysis, segregants of chloroplast markers occurring in the zygote have been distinguished from those occurring in zoospore clones. The genes ac1, ac2, and tm1 showed little if any deviation from 1:1 either in zygotic segregation or in zoospore clones. The genes sm2, ery, and spc showed a significant excess of the allele from the mt+ parent in zygotes. However, in zoospores, mt+ excess was seen only when the allele was the mutant (resistant) form but not when it was wild type (sensitive). These results show that the extent of preferential segregation differs in zygotes and in zoospores, and that preferential segregation is influenced by map location and by allele specificity. A comparison of progeny from zygotes mated after 0, 15'', 30'', and 50'' uv irradiation of the mt+ gametes demonstrated the lack of an effect of uv upon allelic segregation ratios. In total, these results exclude the multi-copy model of chloroplast genome segregation suggested by Gillham. Boynton and Lee (1974) and support the diploid model we have previously proposed.

  7. Chloroplast heterogeneity and historical admixture within the genus Malus

    Science.gov (United States)

    Premise of the study: We examined chloroplast DNA sequence variation in 412 samples representing 30 Malus species (including Malus x domestica Borkh.). Malus wild species are of particular interest for providing novel alleles and traits in apple breeding programs, yet the taxonomic status of these s...

  8. Transport Across Chloroplast Membranes: Optimizing Photosynthesis for Adverse Environmental Conditions.

    Science.gov (United States)

    Pottosin, Igor; Shabala, Sergey

    2016-03-01

    Chloroplasts are central to solar light harvesting and photosynthesis. Optimal chloroplast functioning is vitally dependent on a very intensive traffic of metabolites and ions between the cytosol and stroma, and should be attuned for adverse environmental conditions. This is achieved by an orchestrated regulation of a variety of transport systems located at chloroplast membranes such as porines, solute channels, ion-specific cation and anion channels, and various primary and secondary active transport systems. In this review we describe the molecular nature and functional properties of the inner and outer envelope and thylakoid membrane channels and transporters. We then discuss how their orchestrated regulation affects thylakoid structure, electron transport and excitation energy transfer, proton-motive force partition, ion homeostasis, stromal pH regulation, and volume regulation. We link the activity of key cation and anion transport systems with stress-specific signaling processes in chloroplasts, and discuss how these signals interact with the signals generated in other organelles to optimize the cell performance, with a special emphasis on Ca(2+) and reactive oxygen species signaling. PMID:26597501

  9. Complete Chloroplast Genome Sequence of Phagomixotrophic Green Alga Cymbomonas tetramitiformis

    Science.gov (United States)

    Paasch, Amber E.; Graham, Linda E.; Kim, Eunsoo

    2016-01-01

    We report here the complete chloroplast genome sequence of Cymbomonas tetramitiformis strain PLY262, which is a prasinophycean green alga that retains a phagomixotrophic mode of nutrition. The genome is 84,524 bp in length, with a G+C content of 37%, and contains 3 rRNAs, 26 tRNAs, and 76 protein-coding genes. PMID:27313295

  10. Selenocystamine improves protein accumulation in chloroplasts of eukaryotic green algae

    OpenAIRE

    Ferreira-Camargo, Livia S; Tran, Miller; Beld, Joris; Burkart, Michael D.; Mayfield, Stephen P

    2015-01-01

    Eukaryotic green algae have become an increasingly popular platform for recombinant proteins production. In particular, Chlamydomonas reinhardtii, has garnered increased attention for having the necessary biochemical machinery to produce vaccines, human antibodies and next generation cancer targeting immunotoxins. While it has been shown that chloroplasts contain chaperones, peptidyl prolylisomerases and protein disulfide isomerases that facilitate these complex proteins folding and assembly,...

  11. Global Chloroplast Phylogeny and Biogeography of Bracken (Pteridium: Dennstaedtiaceae)

    OpenAIRE

    J.P.;; Thomson, J. A.; Stratford, J. K.; Paul G Wolf

    2009-01-01

    Bracken ferns (genus Pteridium) represent an ancient species complex with a natural worldwide distribution. Pteridium has historically been treated as comprising a single species, but recent treatments have recognized several related species. Phenotypic plasticity, geographically structured morphological variation, and geographically biased sampling have all contributed to taxonomic confusion in the genus. We sampled bracken specimens worldwide and used variable regions of the chloroplast gen...

  12. Structure of "Arabidopsis" chloroplastic monothiol glutaredoxin AtGRXcp

    Science.gov (United States)

    Monothiol glutaredoxins (Grxs) play important roles in maintaining redox homeostasis in living cells and are conserved across species. "Arabidopsis thaliana" monothiol glutaredoxin AtGRXcp, is critical for protection from oxidative stress in chloroplasts. The crystal structure of AtGRXcp has been de...

  13. Evolution of the Cp-Actin-based Motility System of Chloroplasts in Green Plants.

    Science.gov (United States)

    Suetsugu, Noriyuki; Wada, Masamitsu

    2016-01-01

    During the course of green plant evolution, numerous light responses have arisen that optimize their growth under fluctuating light conditions. The blue light receptor phototropin mediates several photomovement responses at the tissue, cellular and organelle levels. Chloroplast photorelocation movement is one such photomovement response, and is found not only in most green plants, but also in some red algae and photosynthetic stramenopiles. In general, chloroplasts move toward weak light to maximally capture photosynthetically active radiation (the chloroplast accumulation response), and they move away from strong light to avoid photodamage (the avoidance response). In land plants, chloroplast movement is dependent on specialized actin filaments, chloroplast-actin filaments (cp-actin filaments). Through molecular genetic analysis using Arabidopsis thaliana, many molecular factors that regulate chloroplast photorelocation were identified. In this Perspective, we discuss the evolutionary history of the molecular mechanism for chloroplast photorelocation movement in green plants in view of cp-actin filaments. PMID:27200035

  14. Senescence-Associated Vacuoles, a Specific Lytic Compartment for Degradation of Chloroplast Proteins?

    Directory of Open Access Journals (Sweden)

    Cristian A. Carrión

    2014-11-01

    Full Text Available Degradation of chloroplasts and chloroplast components is a distinctive feature of leaf senescence. In spite of its importance in the nutrient economy of plants, knowledge about the mechanism(s involved in the breakdown of chloroplast proteins is incomplete. A novel class of vacuoles, “senescence-associated vacuoles” (SAVs, characterized by intense proteolytic activity appear during senescence in chloroplast-containing cells of leaves. Since SAVs contain some chloroplast proteins, they are candidate organelles to participate in chloroplast breakdown. In this review we discuss the characteristics of SAVs, and their possible involvement in the degradation of Rubisco, the most abundant chloroplast protein. Finally, SAVs are compared with other extra-plastidial protein degradation pathways operating in senescing leaves.

  15. Chloroplast DNA variation and phylogeography of Ligularia tongolensis (Asteraceae), a species endemic to the Hengduan Mountains region of China

    Institute of Scientific and Technical Information of China (English)

    Jin-Feng WANG; Yue-Zhi PAN; Xun GONG; Yu-Chung CHIANG; Chiaki KURODA

    2011-01-01

    In this research, we aimed to study the genetic variation and phylogeographic pattern of Ligularia tongolensis, a perennial herb endemic to the Hengduan Mountains region of China. We sequenced two chloroplast DNA (cpDNA) intergenic spacers (trnQ-5'rps 16, trnL-rpl32) in 140 individuals from 14 populations of three groups (Jinshajiang vs. Yalongjiang vs. Wumeng) within this species range. High levels of haplotype diversity (Hd= 0.814)and total genetic diversity (Ht = 0.862) were detected at the species level, based on a total of 12 haplotypes identified.Low levels of intrapopulation diversity (Hs = 0.349), high levels of genetic divergence (Gst = 0.595, Nst = 0.614,Fst = 0.597), and the absence of isolation by distance tests were also found in L. tongolensis. Furthermore, H2 and H5, the dominant haplotypes that located at internal nodes and deviated from extinct ancestral haplotype in the network, were found to be shared between Jinshajiang and Yalongjiang groups. These results indicate that past fragmentation may be the important factor responsible for the present phylogeographical pattern of L. tongolensis.Meanwhile, the locations occupied by each group might have served as independent refugia for L. tongolensis during the Quaternary glaciation. Unimodal mismatch distribution and star-like genealogies indicated this species underwent past demographic expansion events, with expansion ages of 274 ka BP.

  16. Chloroplast Genome Sequence of the Moss Tortula ruralis: Gene Content and Structural Arrangement Relative to Other Green Plant Chloroplast Genomes

    Science.gov (United States)

    Tortula ruralis, a widely distributed moss species in the family Pottiaceae, is increasingly being used as a model organism for the study of desiccation tolerance and mechanisms of cellular repair. In this paper, we present the chloroplast genome sequence of Tortula ruralis, only the second publishe...

  17. Social capital and health: evidence that ancestral trust promotes health among children of immigrants.

    Science.gov (United States)

    Ljunge, Martin

    2014-12-01

    This paper presents evidence that generalized trust promotes health. Children of immigrants in a broad set of European countries with ancestry from across the world are studied. Individuals are examined within country of residence using variation in trust across countries of ancestry. The approach addresses reverse causality and concerns that the trust measure picks up institutional factors in the individual's contextual setting. There is a significant positive estimate of ancestral trust in explaining self-assessed health. The finding is robust to accounting for individual, parental, and extensive ancestral country characteristics. Individuals with higher ancestral trust are also less likely to be hampered by health problems in their daily life, providing evidence of trust influencing real life outcomes. Individuals with high trust feel and act healthier, enabling a more productive life. PMID:25464341

  18. Reconstructed Ancestral Enzymes Impose a Fitness Cost upon Modern Bacteria Despite Exhibiting Favourable Biochemical Properties.

    Science.gov (United States)

    Hobbs, Joanne K; Prentice, Erica J; Groussin, Mathieu; Arcus, Vickery L

    2015-10-01

    Ancestral sequence reconstruction has been widely used to study historical enzyme evolution, both from biochemical and cellular perspectives. Two properties of reconstructed ancestral proteins/enzymes are commonly reported--high thermostability and high catalytic activity--compared with their contemporaries. Increased protein stability is associated with lower aggregation rates, higher soluble protein abundance and a greater capacity to evolve, and therefore, these proteins could be considered "superior" to their contemporary counterparts. In this study, we investigate the relationship between the favourable in vitro biochemical properties of reconstructed ancestral enzymes and the organismal fitness they confer in vivo. We have previously reconstructed several ancestors of the enzyme LeuB, which is essential for leucine biosynthesis. Our initial fitness experiments revealed that overexpression of ANC4, a reconstructed LeuB that exhibits high stability and activity, was only able to partially rescue the growth of a ΔleuB strain, and that a strain complemented with this enzyme was outcompeted by strains carrying one of its descendants. When we expanded our study to include five reconstructed LeuBs and one contemporary, we found that neither in vitro protein stability nor the catalytic rate was correlated with fitness. Instead, fitness showed a strong, negative correlation with estimated evolutionary age (based on phylogenetic relationships). Our findings suggest that, for reconstructed ancestral enzymes, superior in vitro properties do not translate into organismal fitness in vivo. The molecular basis of the relationship between fitness and the inferred age of ancestral LeuB enzymes is unknown, but may be related to the reconstruction process. We also hypothesise that the ancestral enzymes may be incompatible with the other, contemporary enzymes of the metabolic network. PMID:26349578

  19. Learning the Languages of the Chloroplast: Retrograde Signaling and Beyond.

    Science.gov (United States)

    Chan, Kai Xun; Phua, Su Yin; Crisp, Peter; McQuinn, Ryan; Pogson, Barry J

    2016-04-29

    The chloroplast can act as an environmental sensor, communicating with the cell during biogenesis and operation to change the expression of thousands of proteins. This process, termed retrograde signaling, regulates expression in response to developmental cues and stresses that affect photosynthesis and yield. Recent advances have identified many signals and pathways-including carotenoid derivatives, isoprenes, phosphoadenosines, tetrapyrroles, and heme, together with reactive oxygen species and proteins-that build a communication network to regulate gene expression, RNA turnover, and splicing. However, retrograde signaling pathways have been viewed largely as a means of bilateral communication between organelles and nuclei, ignoring their potential to interact with hormone signaling and the cell as a whole to regulate plant form and function. Here, we discuss new findings on the processes by which organelle communication is initiated, transmitted, and perceived, not only to regulate chloroplastic processes but also to intersect with cellular signaling and alter physiological responses. PMID:26735063

  20. The complete chloroplast genome sequence of Fagopyrum cymosum.

    Science.gov (United States)

    Yang, Jun; Lu, Chaolong; Shen, Qi; Yan, Yuying; Xu, Changjiang; Song, Chi

    2016-07-01

    Fagopyrum cymosum is a traditional medicinal plant. In this study, the complete chloroplast genome of Fagopyrum cymosum is presented. The total genome size is 160,546 bp in length, containing a pair of inverted repeats (IRs) of 32,598 bp, separated by large single copy (LSC) and small single copy (SSC) of 84,237 bp and 11,014 bp, respectively. Overall GC contents of the genome were 36.9%. The chloroplast genome harbors 126 annotated genes, including 91 protein coding genes, 29 tRNA genes, and six rRNA genes. Eighteen genes contain one or two introns. Phylogenetic analyses indicated a clear evolutionary relationship among species of Caryophyllales. PMID:26119127

  1. The complete chloroplast genome of Torreya fargesii (Taxaceae).

    Science.gov (United States)

    Tao, Ke; Gao, Lei; Li, Jia; Chen, Shanshan; Su, Yingjuan; Wang, Ting

    2016-09-01

    The complete chloroplast genome sequence of Torreya fargesii (Taxaceae), a relic plant endemic to China, is presented in this study. The genome is 137 075 bp in length, with 35.47% average GC content. One copy of the large inverted repeats is lost from this genome. The T. fargesii chloroplast genome encodes 118 unique genes, in which trnI-CAU, trnQ-UUG, trnN-GUU are duplicated. Protein-coding, tRNA and rRNA genes represent 54.7%, 1.9% and 3.4% of the genome, respectively. There are 17 intron-containing genes, of which 6 are tRNA genes. A maximum likelihood phylogenetic analysis revealed a strong sister relationship between Torreya and Amentotaxus. PMID:27158868

  2. The complete chloroplast genome of North American ginseng, Panax quinquefolius.

    Science.gov (United States)

    Han, Zeng-Jie; Li, Wei; Liu, Yuan; Gao, Li-Zhi

    2016-09-01

    We report complete nucleotide sequence of the Panax quinquefolius chloroplast genome using next-generation sequencing technology. The genome size is 156 359 bp, including two inverted repeats (IRs) of 52 153 bp, separated by the large single-copy (LSC 86 184 bp) and small single-copy (SSC 18 081 bp) regions. This cp genome encodes 114 unigenes (80 protein-coding genes, four rRNA genes, and 30 tRNA genes), in which 18 are duplicated in the IR regions. Overall GC content of the genome is 38.08%. A phylogenomic analysis of the 10 complete chloroplast genomes from Araliaceae using Daucus carota from Apiaceae as outgroup showed that P. quinquefolius is closely related to the other two members of the genus Panax, P. ginseng and P. notoginseng. PMID:27158867

  3. Chloroplast engineering: boon for third - world countries as therapeutic proteins

    Directory of Open Access Journals (Sweden)

    M. Kumari

    2014-12-01

    Full Text Available Chloroplasts are the site of photosynthesis in plants mostly seen in leaves and some eukaryotic algae that provides the primary sources of the world’s food productivity. Plastids of higher plants are generally semiautonomous with 120–150 kb genome. Chloroplast transformation has become an attractive alternative to nuclear gene transformation due to its advantages, high protein levels, the feasibility of expressing multiple proteins from polycistronic mRNAs, and gene containment through the lack of pollen transmission. The review presents the recent trends and methods for plastid genome engineering and transgene expression and summarizes the potential of plastid transformation in various fields of biotechnology and also as a source of therapeutic proteins.

  4. Localized hypermutation and associated gene losses in legume chloroplast genomes

    OpenAIRE

    KAVANAGH, THOMAS; WOLFE, KENNETH; POWELL, ANTOINETTE

    2010-01-01

    PUBLISHED Point mutations result from errors made during DNA replication or repair, so they are usually expected to be homogeneous across all regions of a genome. However, we have found a region of chloroplast DNA in plants related to sweetpea (Lathyrus) whose local point mutation rate is at least 20 times higher than elsewhere in the same molecule. There are very few precedents for such heterogeneity in any genome, and we suspect that the hypermutable region may be subject to an unusual p...

  5. Protein-Induced Modulation of Chloroplast Membrane Morphology

    OpenAIRE

    Machettira, Anu B.; Groß, Lucia E.; Tillmann, Bodo; Weis, Benjamin L.; Englich, Gisela; Sommer, Maik S.; Königer, Martina; Schleiff, Enrico

    2012-01-01

    Organelles are surrounded by membranes with a distinct lipid and protein composition. While it is well established that lipids affect protein functioning and vice versa, it has been only recently suggested that elevated membrane protein concentrations may affect the shape and organization of membranes. We therefore analyzed the effects of high chloroplast envelope protein concentrations on membrane structures using an in vivo approach with protoplasts. Transient expression of outer envelope p...

  6. Chloroplast gene sequences and the study of plant evolution.

    OpenAIRE

    Clegg, M T

    1993-01-01

    A large body of sequence data has accumulated for the chloroplast-encoded gene ribulose-1,5-biphosphate carboxylase/oxygenase (rbcL) as the result of a cooperative effort involving many laboratories. The data span all seed plants, including most major lineages from the angiosperms, and as such they provide an unprecedented opportunity to study plant evolutionary history. The full analysis of this large data set poses many problems and opportunities for plant evolutionary biologists and for bi...

  7. Regulation of chloroplast biogenesis: the immutans mutant of Arabidopsis

    Energy Technology Data Exchange (ETDEWEB)

    Rodermel, Steven

    2015-11-16

    The immutans (im) variegation mutant of Arabidopsis is an ideal model to gain insight into factors that control chloroplast biogenesis. im defines the gene for PTOX, a plastoquinol terminal oxidase that participates in control of thylakoid redox. Here, we report that the im defect can be suppressed during the late stages of plant development by gigantea (gi2), which defines the gene for GIGANTEA (GI), a central component of the circadian clock that plays a poorly-understood role in diverse plant developmental processes. imgi2 mutants are late-flowering and display other well-known phenotypes associated with gi2, such as starch accumulation and resistance to oxidative stress. We show that the restoration of chloroplast biogenesis in imgi2 is caused by a developmental-specific de-repression of cytokinin signaling that involves crosstalk with signaling pathways mediated by gibberellin (GA) and SPINDLY (SPY), a GA response inhibitor. Suppression of the plastid defect in imgi2 is likely caused by a relaxation of excitation pressures in developing plastids by factors contributed by gi2, including enhanced rates of photosynthesis and increased resistance to oxidative stress. Interestingly, the suppression phenotype of imgi can be mimicked by crossing im with the starch accumulation mutant, sex1, perhaps because sex1 utilizes pathways similar to gi. We conclude that our studies provide a direct genetic linkage between GIGANTEA and chloroplast biogenesis, and we construct a model of interactions between signaling pathways mediated by gi, GA, SPY, cytokinins, and sex1 that are required for chloroplast biogenesis.

  8. Chloroplast Phylogenomics Indicates that Ginkgo biloba Is Sister to Cycads

    OpenAIRE

    Wu, Chung-Shien; Chaw, Shu-Miaw; Huang, Ya-Yi

    2013-01-01

    Molecular phylogenetic studies have not yet reached a consensus on the placement of Ginkgoales, which is represented by the only living species, Ginkgo biloba (common name: ginkgo). At least six discrepant placements of ginkgo have been proposed. This study aimed to use the chloroplast phylogenomic approach to examine possible factors that lead to such disagreeing placements. We found the sequence types used in the analyses as the most critical factor in the conflicting placements of ginkgo. ...

  9. A skull might lie: modelling ancestral ranges and diet from genes and shape of tree squirrels

    Czech Academy of Sciences Publication Activity Database

    Pečnerová, Patrícia; Moravec, Jiří C.; Martínková, Natália

    2015-01-01

    Roč. 64, č. 6 (2015), s. 1074-1088. ISSN 1063-5157 EU Projects: European Commission(XE) CZ.1.07/2.4.00/17.0138 Institutional support: RVO:68081766 Keywords : Sciurini * multilocus phylogeny * geometric morphometry * speciation * ancestral range reconstruction * diet modelling Subject RIV: EG - Zoology Impact factor: 14.387, year: 2014

  10. Investigating the potential of ancestral state reconstruction algorithms in historical linguistics

    OpenAIRE

    Jäger, Gerhard; List, Johann-Mattis

    2016-01-01

    Current efforts in computational historical linguistics are predominantly concerned with phylogenetic inference. However, methods for ancestral state reconstruction have been only sporadically applied. This is surprising since reconstruction is considered essential both in evolutionary biology and in classical historical linguistics. In contradistinction to phylogenetic algorithms, automatic reconstruction methods presuppose phylogenetic information in order to explain what has evolved whe...

  11. Inheritance of the 8.1 ancestral haplotype in recurrent pregnancy loss

    OpenAIRE

    Kolte, Astrid M.; Nielsen, Henriette S.; Steffensen, Rudi; Crespi, Bernard; Christiansen, Ole B

    2015-01-01

    A segment of DNA called the 8.1 ancestral haplotype is hypothesized to cause fetal loss due to a ‘selfish gene’ effect. The hypothesis was not supported, although the haplotype tended to be inherited more often than expected among girls (p=0.11) in a study of 110 mother-child pairs. Further studies are warranted.

  12. Non-canonical transit peptide for import into the chloroplast.

    Science.gov (United States)

    Miras, Stéphane; Salvi, Daniel; Ferro, Myriam; Grunwald, Didier; Garin, Jérôme; Joyard, Jacques; Rolland, Norbert

    2002-12-01

    The large majority of plastid proteins are nuclear-encoded and, thus, must be imported within these organelles. Unlike most of the outer envelope proteins, targeting of proteins to all other plastid compartments (inner envelope membrane, stroma, and thylakoid) is strictly dependent on the presence of a cleavable transit sequence in the precursor N-terminal region. In this paper, we describe the identification of a new envelope protein component (ceQORH) and demonstrate that its subcellular localization is limited to the inner membrane of the chloroplast envelope. Immunopurification, microsequencing of the natural envelope protein and cloning of the corresponding full-length cDNA demonstrated that this protein is not processed in the N-terminal region during its targeting to the inner envelope membrane. Transient expression experiments in plant cells were performed with truncated forms of the ceQORH protein fused to the green fluorescent protein. These experiments suggest that neither the N-terminal nor the C-terminal are essential for chloroplastic localization of the ceQORH protein. These observations are discussed in the frame of the endosymbiotic theory of chloroplast evolution and suggest that a domain of the ceQORH bacterial ancestor may have evolved so as to exclude the general requirement of an N-terminal plastid transit sequence. PMID:12368288

  13. Chloroplast quality control - balancing energy production and stress.

    Science.gov (United States)

    Woodson, Jesse D

    2016-10-01

    Contents 36 I. 36 II. 37 III. 37 IV. 38 V. 39 VI. 40 VII. 40 40 References 40 SUMMARY: All organisms require the ability to sense their surroundings and adapt. Such capabilities allow them to thrive in a wide range of habitats. This is especially true for plants, which are sessile and have to be genetically equipped to withstand every change in their environment. Plants and other eukaryotes use their energy-producing organelles (i.e. mitochondria and chloroplasts) as such sensors. In response to a changing cellular or external environment, these organelles can emit 'retrograde' signals that alter gene expression and/or cell physiology. This signaling is important in plants, fungi, and animals and impacts diverse cellular functions including photosynthesis, energy production/storage, stress responses, growth, cell death, ageing, and tumor progression. Originally, chloroplast retrograde signals in plants were known to lead to the reprogramming of nuclear transcription. New research, however, has pointed to additional posttranslational mechanisms that lead to chloroplast regulation and turnover in response to stress. Such mechanisms involve singlet oxygen, ubiquitination, the 26S proteasome, and cellular degradation machinery. PMID:27533783

  14. Chloroplast Retrograde Regulation of Heat Stress Responses in Plants.

    Science.gov (United States)

    Sun, Ai-Zhen; Guo, Fang-Qing

    2016-01-01

    It is well known that intracellular signaling from chloroplast to nucleus plays a vital role in stress responses to survive environmental perturbations. The chloroplasts were proposed as sensors to heat stress since components of the photosynthetic apparatus housed in the chloroplast are the major targets of thermal damage in plants. Thus, communicating subcellular perturbations to the nucleus is critical during exposure to extreme environmental conditions such as heat stress. By coordinating expression of stress specific nuclear genes essential for adaptive responses to hostile environment, plants optimize different cell functions and activate acclimation responses through retrograde signaling pathways. The efficient communication between plastids and the nucleus is highly required for such diverse metabolic and biosynthetic functions during adaptation processes to environmental stresses. In recent years, several putative retrograde signals released from plastids that regulate nuclear genes have been identified and signaling pathways have been proposed. In this review, we provide an update on retrograde signals derived from tetrapyrroles, carotenoids, reactive oxygen species (ROS) and organellar gene expression (OGE) in the context of heat stress responses and address their roles in retrograde regulation of heat-responsive gene expression, systemic acquired acclimation, and cellular coordination in plants. PMID:27066042

  15. Chloroplast ultrastructure in leaves of Cucumis sativus chlorophyll mutant

    Directory of Open Access Journals (Sweden)

    Irena Palczewska

    2014-02-01

    Full Text Available The developing and young leaves of Cucumis sativus chlorophyll mutants are yellow, when mature they become green and do not differ in their colour from those of control plants. The mesophyll of yellow leaves contains a diversiform plastid population with a varying degree of defectiveness, which is mainly manifested in the reduction or disorganization of the typical thylakoid system. DNA areas, ribosome-like particles and aggregates of electron-dense material are preserved in the stroma of mutated plastids. Starch grains are deficient. Apart from mutated plastids, chloroplasts with a normal structure, as in control plants, were also observed.The leaf greening process is accompanied by a reconstruction and rearrangement of the inner chloroplast lamellar system and an ability to accumulate starch. However, in the mutant chloroplasts as compared with control-plant ones, an irregular arrangement of grana and reduced number of inter-grana thylakoids can be seen. An osmiophilic substance stored in the stroma of mutated plastids and the vesicles formed from an internal plastid membrane take part in restoration of the membrane system.

  16. Combined effects of light and water stress on chloroplast volume regulation.

    OpenAIRE

    McCain, D.C.

    1995-01-01

    A nuclear magnetic resonance technique was used to measure changes in the water content of Acer platanoides chloroplasts in leaf discs that had reached osmotic equilibrium with external solutions either in the dark or under exposure to light. Results showed that chloroplast volume regulation (CVR) maintained constant water content in the chloroplasts over a range of water potentials in the dark, but CVR failed when the water potential fell below a critical value. The critical potential was lo...

  17. Longevity of guard cell chloroplasts in falling leaves: implication for stomatal function and cellular aging

    Energy Technology Data Exchange (ETDEWEB)

    Zeiger, E.; Schwartz, A.

    1982-11-12

    Guard cell chloroplasts in senescing leaves from 12 species of perennial trees and three species of annual plants survived considerably longer than their mesophyll counterparts. In Ginkgo biloba, stomata from yellow leaves opened during the day and closed at night; guard cell chloroplasts from these leaves showed fluorescence transients associated with electron transport and photophosphorylation. These findings indicate that guard cell chloroplasts are highly conserved throughout the life-span of the leaf and that leaves retain stomatal control during senescence.

  18. Development of the first chloroplast microsatellite loci in Ginkgo biloba (Ginkgoaceae) 1

    OpenAIRE

    Chun-Xiang Xie; Ming-Shui Zhao; Cheng-Xin Fu; Yun-Peng Zhao

    2013-01-01

    Premise of the study: To investigate population genetics, phylogeography, and cultivar origin of Ginkgo biloba, chloroplast microsatellite primers were developed. Methods and Results: Twenty-one chloroplast microsatellite markers were identified referring to the two published chloroplast genomes of G. biloba. Polymorphisms were assessed on four natural populations from the two refugia in China. Eight loci were detected to be polymorphic in these populations. The number of alleles per locus...

  19. CDP1, a novel component of chloroplast division site positioning system in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Min Zhang; Yong Hu; Jingjing Jia; Dapeng Li; Runjie Zhang; Hongbo Gao; Yikun He

    2009-01-01

    Chloroplasts are plant-specific organelles that evolved from endosymbiotic cyanobacteria. They divide through binary fission. Selection of the chloroplast division site is pivotal for the symmetric chloroplast division. In E. coli, positioning of the division site at the midpoint of the cell is regulated by dynamic oscillation of the Min system, which includes MinC, MinD and MinE. Homologs of Mind and MinE in plants are involved in chloroplast division. The homolog of MinC still has not been identified in higher plants. However, an FtsZ-like protein, ARC3, was found to be involved in chloroplast division site positioning. Here, we report that chloroplast division site positioning 1 (AtCDP1) is a novel chloroplast division protein involved in chloroplast division site placement in Arabidopsis. AtCDP1 was dis-covered by screening an Arabidopsis cDNA expression library in bacteria for colonies with a cell division phenotype. AtCDP1 is exclusively expressed in young green tissues in Arabidopsis. Elongated chloroplasts with multiple division sites were observed in the loss-of-function cdpl mutant. Overexpression of AtCDPI caused a chloroplast division phe-notype too. Protein interaction assays suggested that AtCDP1 may mediate the chloroplast division site positioning through the interaction with ARC3. Overall, our results indicate that AtCDP1 is a novel component of the chloroplast division site positioning system, and the working mechanism of this system is different from that of the traditional MinCDE system in prokaryotic cells.

  20. High-Throughput Sequencing of Three Lemnoideae (Duckweeds) Chloroplast Genomes from Total DNA

    OpenAIRE

    Wang, Wenqin; Messing, Joachim

    2011-01-01

    Background Chloroplast genomes provide a wealth of information for evolutionary and population genetic studies. Chloroplasts play a particularly important role in the adaption for aquatic plants because they float on water and their major surface is exposed continuously to sunlight. The subfamily of Lemnoideae represents such a collection of aquatic species that because of photosynthesis represents one of the fastest growing plant species on earth. Methods We sequenced the chloroplast genomes...

  1. Effect of growth temperature on chloroplast structure and activity in barley.

    Science.gov (United States)

    Smillie, R M; Critchley, C; Bain, J M; Nott, R

    1978-08-01

    Seedlings of barley (Hordeum vulgare L. cv. Abyssinian) were grown at constant temperature and light intensity and the properties and structure of chloroplasts in the primary leaf were examined. Seventeen growth temperatures ranging from 2 to 37 C were employed. Three major effects of the growth temperature were seen. (a) At very low and high growth temperatures chloroplast biogenesis was inhibited. This occurred in plants grown at temperatures above 32 C while growth at 2 C resulted in a mixed population of pale yellow, pale green, and green plants. (b) Chloroplasts were produced at all other temperatures tested but growth temperatures within a few degrees of those inhibitory to chloroplast development resulted in chloroplasts with abnormal properties and structure. Chloroplasts in the green plants grown at 2 and 5 C showed a number of structural peculiarities, including a characteristic crimping of granal thylakoids. Photoreductive activity, measured using ferricyanide as the Hill oxidant in the presence of gramicidin D, was high, but this activity in chloroplasts isolated from plants grown at 2 C showed thermal inactivation at temperatures 5 degrees lower than was the case with plants grown at higher temperatures. High growth temperatures (30 to 32 C) yielded chloroplasts with reduced photoreductive activity and a tendency toward the formation of large grana and disorientation of the lamellar systems with respect to one another. Chloroplasts of the most affected plants (grown at 32 C) frequently contained a very large elongated granum, with narrow intrathylakoid spaces. (c) Photoreductive activity was not constant at intermediate growth temperatures but steadily declined with decreasing growth temperatures between 27 and 11 C. Some alterations in chloroplast structure were also observed.The changes in chloroplast activity and structure indicate that acclimation to temperature takes place over the entire temperature range in which chloroplast development is

  2. Frequency of carriers of 8.1 ancestral haplotype and its fragments in two Caucasian populations.

    Science.gov (United States)

    Kiszel, Petra; Kovács, Margit; Szalai, Csaba; Yang, Yan; Pozsonyi, Eva; Blaskó, Bernadett; Laki, Judit; Prohászka, Zoltán; Fazakas, Adám; Pánczél, Pál; Hosszúfalusi, Nóra; Rajczy, Katalin; Wu, Yee-Ling; Chung, Erwin K; Zhou, Bi; Blanchong, Carol A; Vatay, Agnes; Yu, C Yung; Füst, G

    2007-01-01

    Within the human MHC region larger stretches of conserved DNA, called conserved ancestral haplotypes exist. However, many MHC haplotypes contain only fragments of an ancestral haplotype. Little is known, however, on relative distribution of the ancestral haplotypes to their fragments. Therefore we determined the frequency of carriers of the whole ancestral haplotype 8.1 (AH8.1) and its fragments in 127 healthy Hungarian people, 101 healthy Ohioian females, and in nine Hungarian families. The HLA-DQ2, HLA-DR3(17), RAGE -429C allele, the mono-S-C4B genotype, the HSP70-2 1267G allele and the TNF -308A (TNF2) allele were used as markers of the AH8.1. Frequency of carriers of the whole AH8.1 and its fragments was similar in the both populations. 18% of the subjects carried the whole AH8.1 in at least one chromosome, while 17-20%, 36-39%, and 24-29%, respectively carried two or three constituents of the haplotype, only one constituent or none of them. Similar results were obtained in the family study. In addition, marked differences were found in the relationship of the constituents' alleles to the whole AH8.1. In both populations, 29%, 50-59%, 52-56% and 76-96%, respectively of the carriers of HSP70-2 1267G, RAGE-429C, TNF2, and mono-S carriers carried the whole 8.1 haplotype. These findings may have important implications for studies of the disease associations with different MHC ancestral haplotypes. PMID:17558713

  3. Regulation of chloroplast number and DNA synthesis in higher plants. Final report, August 1995--August 1996

    Energy Technology Data Exchange (ETDEWEB)

    Mullet, J.E.

    1997-06-17

    The long term objective of this research is to understand the process of chloroplast development and its coordination with leaf development in higher plants. This is important because the photosynthetic capacity of plants is directly related to leaf and chloroplast development. This research focused on obtaining a detailed description of leaf development and the early steps in chloroplast development including activation of plastid DNA synthesis, changes in plastid DNA copy number, activation of chloroplast transcription and increases in plastid number per cell. The research focused on the isolation of the plastid DNA polymerase, and identification of genetic mutants which are altered in their accumulation of plastid DNA and plastid number per cell.

  4. Sonication-based isolation and enrichment of Chlorella protothecoides chloroplasts for illumina genome sequencing

    Energy Technology Data Exchange (ETDEWEB)

    Angelova, Angelina [University of Arizona; Park, Sang-Hycuk [University of Arizona; Kyndt, John [Bellevue University; Fitzsimmons, Kevin [University of Arizona; Brown, Judith K [University of Arizona

    2013-09-01

    With the increasing world demand for biofuel, a number of oleaginous algal species are being considered as renewable sources of oil. Chlorella protothecoides Krüger synthesizes triacylglycerols (TAGs) as storage compounds that can be converted into renewable fuel utilizing an anabolic pathway that is poorly understood. The paucity of algal chloroplast genome sequences has been an important constraint to chloroplast transformation and for studying gene expression in TAGs pathways. In this study, the intact chloroplasts were released from algal cells using sonication followed by sucrose gradient centrifugation, resulting in a 2.36-fold enrichment of chloroplasts from C. protothecoides, based on qPCR analysis. The C. protothecoides chloroplast genome (cpDNA) was determined using the Illumina HiSeq 2000 sequencing platform and found to be 84,576 Kb in size (8.57 Kb) in size, with a GC content of 30.8 %. This is the first report of an optimized protocol that uses a sonication step, followed by sucrose gradient centrifugation, to release and enrich intact chloroplasts from a microalga (C. prototheocoides) of sufficient quality to permit chloroplast genome sequencing with high coverage, while minimizing nuclear genome contamination. The approach is expected to guide chloroplast isolation from other oleaginous algal species for a variety of uses that benefit from enrichment of chloroplasts, ranging from biochemical analysis to genomics studies.

  5. Phosphorus compounds, proteins, nuclease and acid phosphatase activities in isolated spinach chloroplasts

    Directory of Open Access Journals (Sweden)

    E. Mikulska

    2015-05-01

    Full Text Available This paper deals with attempts to elaborate a simple method of spinach chloroplast isolation ensuring a high proportion of intact chloroplasts. We obtained 3 preparations of isolated chloroplasts. Several preliminary analyses of the obtained chloroplast fraction were also performed. Phosphorus compounds, total protein and the enzyme activities of RNase, DNase and GPase were determined. We found: 0,36-0,59% of RNA, 0,19-0,24% of DNA, 2,1-2,9% of phospholipids and 26-28% of protein. RNase activity was very high.

  6. Chloroplast transformation for engineering of photosynthesis.

    Science.gov (United States)

    Hanson, Maureen R; Gray, Benjamin N; Ahner, Beth A

    2013-01-01

    Many efforts are underway to engineer improvements in photosynthesis to meet the challenges of increasing demands for food and fuel in rapidly changing environmental conditions. Various transgenes have been introduced into either the nuclear or plastid genomes in attempts to increase photosynthetic efficiency. We examine the current knowledge of the critical features that affect levels of expression of plastid transgenes and protein accumulation in transplastomic plants, such as promoters, 5' and 3' untranslated regions, RNA-processing sites, translation signals and amino acid sequences that affect protein turnover. We review the prior attempts to manipulate the properties of ribulose-1,5-bisphosphate carboxylase oxygenase (Rubisco) through plastid transformation. We illustrate how plastid operons could be created for expression of the multiple genes needed to introduce new pathways or enzymes to enhance photosynthetic rates or reduce photorespiration. We describe here the past accomplishments and future prospects for manipulating plant enzymes and pathways to enhance carbon assimilation through plastid transformation. PMID:23162121

  7. Whole genome sequencing of enriched chloroplast DNA using the Illumina GAII platform

    Directory of Open Access Journals (Sweden)

    Shepherd Lara D

    2010-09-01

    Full Text Available Abstract Background Complete chloroplast genome sequences provide a valuable source of molecular markers for studies in molecular ecology and evolution of plants. To obtain complete genome sequences, recent studies have made use of the polymerase chain reaction to amplify overlapping fragments from conserved gene loci. However, this approach is time consuming and can be more difficult to implement where gene organisation differs among plants. An alternative approach is to first isolate chloroplasts and then use the capacity of high-throughput sequencing to obtain complete genome sequences. We report our findings from studies of the latter approach, which used a simple chloroplast isolation procedure, multiply-primed rolling circle amplification of chloroplast DNA, Illumina Genome Analyzer II sequencing, and de novo assembly of paired-end sequence reads. Results A modified rapid chloroplast isolation protocol was used to obtain plant DNA that was enriched for chloroplast DNA, but nevertheless contained nuclear and mitochondrial DNA. Multiply-primed rolling circle amplification of this mixed template produced sufficient quantities of chloroplast DNA, even when the amount of starting material was small, and improved the template quality for Illumina Genome Analyzer II (hereafter Illumina GAII sequencing. We demonstrate, using independent samples of karaka (Corynocarpus laevigatus, that there is high fidelity in the sequence obtained from this template. Although less than 20% of our sequenced reads could be mapped to chloroplast genome, it was relatively easy to assemble complete chloroplast genome sequences from the mixture of nuclear, mitochondrial and chloroplast reads. Conclusions We report successful whole genome sequencing of chloroplast DNA from karaka, obtained efficiently and with high fidelity.

  8. Two interacting coiled-coil proteins, WEB1 and PMI2, maintain the chloroplast photorelocation movement velocity in Arabidopsis

    OpenAIRE

    Kodama, Yutaka; Suetsugu, Noriyuki; Kong, Sam-Geun; Wada, Masamitsu

    2010-01-01

    Chloroplasts move toward weak light (accumulation response) and away from strong light (avoidance response). The fast and accurate movement of chloroplasts in response to ambient light conditions is essential for efficient photosynthesis and photodamage prevention in chloroplasts. Here, we report that two Arabidopsis mutants, weak chloroplast movement under blue light 1 (web1) and web2, are defective in both the avoidance and the accumulation responses. Map-based cloning revealed that both ge...

  9. Effect of alkyl-N-phenylcarbamates on photochemical activity of spinach chloroplasts

    International Nuclear Information System (INIS)

    This study is aimed to investigate the effect of alkyl-N-phenylcarbamates on photosynthetic electron transport in spinach chloroplasts, to determine site of action in the photosynthetic apparatus of spinach chloroplasts and to find correlations between their structure and biological activity. (authors)

  10. Treatment with antibiotics that interfere with peptidoglycan biosynthesis inhibits chloroplast division in the desmid Closterium.

    Directory of Open Access Journals (Sweden)

    Hiroko Matsumoto

    Full Text Available Charophytes is a green algal group closely related to land plants. We investigated the effects of antibiotics that interfere with peptidoglycan biosynthesis on chloroplast division in the desmid Closterium peracerosum-strigosum-littorale complex. To detect cells just after division, we used colchicine, which inhibits Closterium cell elongation after division. Although normal Closterium cells had two chloroplasts before and after cell division, cells treated with ampicillin, D-cycloserine, or fosfomycin had only one chloroplast after cell division, suggesting that the cells divided without chloroplast division. The antibiotics bacitracin and vancomycin showed no obvious effect. Electron microscopic observation showed that irregular-shaped chloroplasts existed in ampicillin-treated Closterium cells. Because antibiotic treatments resulted in the appearance of long cells with irregular chloroplasts and cell death, we counted cell types in the culture. The results suggested that cells with one chloroplast appeared first and then a huge chloroplast was generated that inhibited cell division, causing elongation followed by cell death.

  11. The Unicellular Green Alga Chlamydomonas reinhardtii as an Experimental System to Study Chloroplast RNA Metabolism

    Science.gov (United States)

    Nickelsen, J.; Kück, U.

    Chloroplasts are typical organelles of photoautotrophic eukaryotic cells which drive a variety of functions, including photosynthesis. For many years the unicellular green alga Chlamydomonas reinhardtii has served as an experimental organism for studying photosynthetic processes. The recent development of molecular tools for this organism together with efficient methods of genetic analysis and the availability of many photosynthesis mutants has now made this alga a powerful model system for the analysis of chloroplast biogenesis. For example, techniques have been developed to transfer recombinant DNA into both the nuclear and the chloroplast genome. This allows both complementation tests and analyses of gene functions in vivo. Moreover, site-specific DNA recombinations in the chloroplast allow targeted gene disruption experiments which enable a "reverse genetics" to be performed. The potential of the algal system for the study of chloroplast biogenesis is illustrated in this review by the description of regulatory systems of gene expression involved in organelle biogenesis. One example concerns the regulation of trans-splicing of chloroplast mRNAs, a process which is controlled by both multiple nuclear- and chloroplast-encoded factors. The second example involves the stabilization of chloroplast mRNAs. The available data lead us predict distinct RNA elements, which interact with trans-acting factors to protect the RNA against nucleolytic attacks.

  12. Punctuated evolution and transitional hybrid network in an ancestral cell cycle of fungi

    Science.gov (United States)

    Medina, Edgar M; Turner, Jonathan J; Gordân, Raluca; Skotheim, Jan M; Buchler, Nicolas E

    2016-01-01

    Although cell cycle control is an ancient, conserved, and essential process, some core animal and fungal cell cycle regulators share no more sequence identity than non-homologous proteins. Here, we show that evolution along the fungal lineage was punctuated by the early acquisition and entrainment of the SBF transcription factor through horizontal gene transfer. Cell cycle evolution in the fungal ancestor then proceeded through a hybrid network containing both SBF and its ancestral animal counterpart E2F, which is still maintained in many basal fungi. We hypothesize that a virally-derived SBF may have initially hijacked cell cycle control by activating transcription via the cis-regulatory elements targeted by the ancestral cell cycle regulator E2F, much like extant viral oncogenes. Consistent with this hypothesis, we show that SBF can regulate promoters with E2F binding sites in budding yeast. DOI: http://dx.doi.org/10.7554/eLife.09492.001 PMID:27162172

  13. Chloroplast genetics of chlamydomonas. II. Mapping by cosegregation frequency analysis

    International Nuclear Information System (INIS)

    This paper presents segregation and cosegregation data for a set of 15 chloroplast genes of Chlamydomonas, and uses these data to generate a linear map of the chloroplast genome. The data were derived from pedigree analysis of a total of 1596 zoospore clones resulting from 12 crosses in each of which 4 to 7 pairs of chloroplast alleles were segregating. The crosses are a subset of those previously described. By means of pedigree analysis, Type III segregations (nonreciprocal conversion-like events) were distinguished from Type III segregations (reciprocal events). The average frequency of Type II segregation was found to be the same for all 15 genes, indicating randomness of this event with respect to map location. Type III segregations occurred with a different and characteristic frequency for each gene, and were interpreted as a measure of the distance of each gene from the postulated centromere-like attachment point. Cosegregations, involving two or more genes, occurred with frequencies characteristic of the particular genes and much lower than expected for the product of single-gene events, indicating strong positive interference. Pairwise cosegregation frequencies provided unambiguous data for the gene order, confirmed by cosegregation runs of three or more genes. Apparent lengths of cosegregation runs, as fractions of the total map, indicate much longer stretches of gene conversion-like events than have been reported for other genetic systems. Comparisons of cosegregation frequencies in cross 20 after 15'', 30'', and 15'' uv irradiation of the mt+ before mating, indicate little if any consistent effect of this irradiation on segregation events

  14. Chloroplasts Are Central Players in Sugar-Induced Leaf Growth.

    Science.gov (United States)

    Van Dingenen, Judith; De Milde, Liesbeth; Vermeersch, Mattias; Maleux, Katrien; De Rycke, Riet; De Bruyne, Michiel; Storme, Véronique; Gonzalez, Nathalie; Dhondt, Stijn; Inzé, Dirk

    2016-05-01

    Leaves are the plant's powerhouses, providing energy for all organs through sugar production during photosynthesis. However, sugars serve not only as a metabolic energy source for sink tissues but also as signaling molecules, affecting gene expression through conserved signaling pathways to regulate plant growth and development. Here, we describe an in vitro experimental assay, allowing one to alter the sucrose (Suc) availability during early Arabidopsis (Arabidopsis thaliana) leaf development, with the aim to identify the affected cellular and molecular processes. The transfer of seedlings to Suc-containing medium showed a profound effect on leaf growth by stimulating cell proliferation and postponing the transition to cell expansion. Furthermore, rapidly after transfer to Suc, mesophyll cells contained fewer and smaller plastids, which are irregular in shape and contain fewer starch granules compared with control mesophyll cells. Short-term transcriptional responses after transfer to Suc revealed the repression of well-known sugar-responsive genes and multiple genes encoded by the plastid, on the one hand, and up-regulation of a GLUCOSE-6-PHOSPHATE TRANSPORTER (GPT2), on the other hand. Mutant gpt2 seedlings showed no stimulation of cell proliferation and no repression of chloroplast-encoded transcripts when transferred to Suc, suggesting that GPT2 plays a critical role in the Suc-mediated effects on early leaf growth. Our findings, therefore, suggest that induction of GPT2 expression by Suc increases the import of glucose-6-phosphate into the plastids that would repress chloroplast-encoded transcripts, restricting chloroplast differentiation. Retrograde signaling from the plastids would then delay the transition to cell expansion and stimulate cell proliferation. PMID:26932234

  15. Diaspora of diaspora: Adyge-Abkhaz returnees in the ancestral homeland

    OpenAIRE

    Erciyes, Cemre

    2008-01-01

    Focusing on the diasporic characteristics shown by ancestral return migrants, this case study looks at the Abkhaz-Adyge (Circassian) returnees from Turkey to the Caucasus and how they become the “diaspora of the diaspora.” The next generations of diasporans continue to dream of return, and, with recent developments in communication technologies and cheaper transportation, many find ways to realize this dream. There are many different forms of return, but some “return-migrate” and settle in an...

  16. COMPONENTES NUTRICIONALES Y ANTIOXIDANTES DE DOS ESPECIES DE GUAJE (Leucaena spp.): UN RECURSO ANCESTRAL SUBUTILIZADO

    OpenAIRE

    Nallely Román-Cortés; María del Rosario García-Mateos; Ana María Castillo-González; Jaime Sahagún-Castellanos; Adelina Jiménez-Arellanes

    2014-01-01

    El guaje ( Leucaena spp.) es una planta de vaina y semillas comestibles, un recurso ancestral subutilizado por los pueblos mesoamericanos. El valor nutricional y nutracéutico del guaje se desconoce pese a su consumo vigente en las poblaciones rurales. El objetivo de este trabajo fue evaluar el contenido de minerales, compo - nentes nutricionales y antioxidantes para contribuir a la revalorización alimentaria del guaje rojo ( L. esculenta Benth.) y verde ( L. leucocephala Lam.). Los contenidos...

  17. The complete chloroplast genome sequence of Curcuma flaviflora (Curcuma).

    Science.gov (United States)

    Zhang, Yan; Deng, Jiabin; Li, Yangyi; Gao, Gang; Ding, Chunbang; Zhang, Li; Zhou, Yonghong; Yang, Ruiwu

    2016-09-01

    The complete chloroplast (cp) genome of Curcuma flaviflora, a medicinal plant in Southeast Asia, was sequenced. The genome size was 160 478 bp in length, with 36.3% GC content. A pair of inverted repeats (IRs) of 26 946 bp were separated by a large single copy (LSC) of 88 008 bp and a small single copy (SSC) of 18 578 bp, respectively. The cp genome contained 132 annotated genes, including 79 protein coding genes, 30 tRNA genes, and four rRNA genes. And 19 of these genes were duplicated in inverted repeat regions. PMID:26367332

  18. Biotin Carboxyl Carrier Protein in Barley Chloroplast Membranes

    DEFF Research Database (Denmark)

    Kannangara, C. G.; Jense, C J

    1975-01-01

    Biotin localized in barley chloroplast lamellae is covalently bound to a single protein with an approximate molecular weight of 21000. It contains one mole of biotin per mole of protein and functions as a carboxyl carrier in the acetyl-CoA carboxylase reaction. The protein was obtained by...... solubilization of the lamellae in phenol/acetic acid/8 M urea. Feeding barley seedlings with [14C]-biotin revealed that the vitamin is not degraded into respiratory substrates by the plant, but is specifically incorporated into biotin carboxyl carrier protein....

  19. The complete chloroplast genome sequence of Hibiscus syriacus.

    Science.gov (United States)

    Kwon, Hae-Yun; Kim, Joon-Hyeok; Kim, Sea-Hyun; Park, Ji-Min; Lee, Hyoshin

    2016-09-01

    The complete chloroplast genome sequence of Hibiscus syriacus L. is presented in this study. The genome is composed of 161 019 bp in length, with a typical circular structure containing a pair of inverted repeats of 25 745 bp of length separated by a large single-copy region and a small single-copy region of 89 698 bp and 19 831 bp of length, respectively. The overall GC content is 36.8%. One hundred and fourteen genes were annotated, including 81 protein-coding genes, 4 ribosomal RNA genes and 29 transfer RNA genes. PMID:26357910

  20. Chloroplast transformation of Platymonas (Tetraselmis subcordiformis with the bar gene as selectable marker.

    Directory of Open Access Journals (Sweden)

    Yulin Cui

    Full Text Available The objective of this research was to establish a chloroplast transformation technique for Platymonas (Tetraselmis subcordiformis. Employing the gfp gene as a reporter and the bar gene as a selectable marker, transformation vectors of P. subcordiformis chloroplast were constructed with endogenous fragments rrn16S-trnI (left and trnA-rrn23S (right as a recombination site of the chloroplast genome. The plasmids were transferred into P. subcordiformis via particle bombardment. Confocal laser scanning microscopy indicated that the green fluorescence protein was localized in the chloroplast of P. subcordiformis, confirming the activity of the Chlamydomonas reinhardtii promoter. Cells transformed with the bar gene were selected using the herbicide Basta. Resistant colonies were analyzed by PCR and Southern blotting, and the results indicated that the bar gene was successfully integrated into the chloroplast genome via homologous recombination. The technique will improve genetic engineering of this alga.

  1. Update on Chloroplast Research: New Tools, New Topics, and New Trends

    Institute of Scientific and Technical Information of China (English)

    Ute Armbruster; Paolo Pesaresi; Mathias Pribil; Alexander Hertle; Dario Leister

    2011-01-01

    Chloroplasts, the green differentiation form of plastids, are the sites of photosynthesis and other important plant functions. Genetic and genomic technologies have greatly boosted the rate of discovery and functional characterization of chloroplast proteins during the past decade. Indeed, data obtained using high-throughput methodologies, in particular proteomics and transcriptomics, are now routinely used to assign functions to chloroplast proteins. Our knowledge of many chloroplast processes, notably photosynthesis and photorespiration, has reached such an advanced state that biotechnological approaches to crop improvement now seem feasible. Meanwhile, efforts to identify the entire complement of chloroplast proteins and their interactions are progressing rapidly, making the organelle a prime target for systems biology research in plants.

  2. Ancestral informative marker selection and population structure visualization using sparse Laplacian eigenfunctions.

    Directory of Open Access Journals (Sweden)

    Jun Zhang

    Full Text Available Identification of a small panel of population structure informative markers can reduce genotyping cost and is useful in various applications, such as ancestry inference in association mapping, forensics and evolutionary theory in population genetics. Traditional methods to ascertain ancestral informative markers usually require the prior knowledge of individual ancestry and have difficulty for admixed populations. Recently Principal Components Analysis (PCA has been employed with success to select SNPs which are highly correlated with top significant principal components (PCs without use of individual ancestral information. The approach is also applicable to admixed populations. Here we propose a novel approach based on our recent result on summarizing population structure by graph laplacian eigenfunctions, which differs from PCA in that it is geometric and robust to outliers. Our approach also takes advantage of the priori sparseness of informative markers in the genome. Through simulation of a ring population and the real global population sample HGDP of 650K SNPs genotyped in 940 unrelated individuals, we validate the proposed algorithm at selecting most informative markers, a small fraction of which can recover the similar underlying population structure efficiently. Employing a standard Support Vector Machine (SVM to predict individuals' continental memberships on HGDP dataset of seven continents, we demonstrate that the selected SNPs by our method are more informative but less redundant than those selected by PCA. Our algorithm is a promising tool in genome-wide association studies and population genetics, facilitating the selection of structure informative markers, efficient detection of population substructure and ancestral inference.

  3. Distinct actions of ancestral vinclozolin and juvenile stress on neural gene expression in the male rat

    Directory of Open Access Journals (Sweden)

    Ross eGillette

    2015-03-01

    Full Text Available Exposure to the endocrine disrupting chemical vinclozolin during gestation of an F0 generation and/or chronic restraint stress during adolescence of the F3 descendants affects behavior, physiology, and gene expression in the brain. Genes related to the networks of growth factors, signaling peptides and receptors, steroid hormone receptors and enzymes, and epigenetic related factors were measured using quantitative polymerase chain reaction via Taqman low density arrays targeting 48 genes in the central amygdaloid nucleus, medial amygdaloid nucleus, medial preoptic area, lateral hypothalamus, and the ventromedial nucleus of the hypothalamus. We found that growth factors are particularly vulnerable to ancestral exposure in the central and medial amygdala; restraint stress during adolescence affected neural growth factors in the medial amygdala. Signaling peptides were affected by both ancestral exposure and stress during adolescence primarily in hypothalamic nuclei. Steroid hormone receptors and enzymes were strongly affected by restraint stress in the medial preoptic area. Epigenetic related genes were affected by stress in the ventromedial hypothalamus and by both ancestral exposure and stress during adolescence independently in the central amygdala. It is noteworthy that the lateral hypothalamus showed no effects of either manipulation. Gene expression is discussed in the context of behavioral and physiological measures previously published.

  4. AAV ancestral reconstruction library enables selection of broadly infectious viral variants.

    Science.gov (United States)

    Santiago-Ortiz, J; Ojala, D S; Westesson, O; Weinstein, J R; Wong, S Y; Steinsapir, A; Kumar, S; Holmes, I; Schaffer, D V

    2015-12-01

    Adeno-associated virus (AAV) vectors have achieved clinical efficacy in treating several diseases. However, enhanced vectors are required to extend these landmark successes to other indications and protein engineering approaches may provide the necessary vector improvements to address such unmet medical needs. To generate new capsid variants with potentially enhanced infectious properties and to gain insights into AAV's evolutionary history, we computationally designed and experimentally constructed a putative ancestral AAV library. Combinatorial variations at 32 amino acid sites were introduced to account for uncertainty in their identities. We then analyzed the evolutionary flexibility of these residues, the majority of which have not been previously studied, by subjecting the library to iterative selection on a representative cell line panel. The resulting variants exhibited transduction efficiencies comparable to the most efficient extant serotypes and, in general, ancestral libraries were broadly infectious across the cell line panel, indicating that they favored promiscuity over specificity. Interestingly, putative ancestral AAVs were more thermostable than modern serotypes and did not use sialic acids, galactose or heparan sulfate proteoglycans for cellular entry. Finally, variants mediated 19- to 31-fold higher gene expression in the muscle compared with AAV1, a clinically used serotype for muscle delivery, highlighting their promise for gene therapy. PMID:26186661

  5. YGL9, encoding the putative chloroplast signal recognition particle 43 kDa protein in rice, is involved in chloroplast development

    Institute of Scientific and Technical Information of China (English)

    WANG Zhong-wei; LI Yun-feng; LING Ying-hua; SANG Xian-chun; HE Guang-hua; ZHANG Tian-quan; XING Ya-di; ZENG Xiao-qin; WANG Ling; LIU Zhong-xian; SHI Jun-qiong; ZHU Xiao-yan; MA Ling

    2016-01-01

    The nuclear-encoded light-harvesting chlorophyla/b-binding proteins (LHCPs) are speciifcaly translocated from the stroma into the thylakoid membrane through the chloroplast signal recognition particle (cpSRP) pathway. The cpSRP is composed of a cpSRP43 protein and a cpSRP54 protein, and it forms a soluble transit complex with LHCP in the chloroplast stroma. Here, we identiifed theYGL9gene that is predicted to encode the probable rice cpSRP43 protein from a rice yelow-green leaf mutant. A phylogenetic tree showed that an important conserved protein family, cpSRP43, is present in almost al green photosynthetic organisms such as higher plants and green algae. Sequence analysis showed that YGL9 comprises a chloroplast transit peptide, three chromodomains and four ankyrin repeats, and the chromodomains and ankyrin repeats are probably involved in protein-protein interactions. Subcelular localization showed that YGL9 is localized in the chloroplast. Expression pattern analysis indicated thatYGL9is mainly expressed in green leaf sheaths and leaves. Quantitative real-time PCR analysis showed that the expression levels of genes associated with pigment metabolism, chloroplast development and photosynthesis were distinctly affected in theygl9mutant. These results indicated thatYGL9 is possibly involved in pigment metabolism, chloroplast development and photosynthesis in rice.

  6. Chloroplast genome sequence of the moss Tortula ruralis: gene content, polymorphism, and structural arrangement relative to other green plant chloroplast genomes

    Directory of Open Access Journals (Sweden)

    Wolf Paul G

    2010-02-01

    Full Text Available Abstract Background Tortula ruralis, a widely distributed species in the moss family Pottiaceae, is increasingly used as a model organism for the study of desiccation tolerance and mechanisms of cellular repair. In this paper, we present the chloroplast genome sequence of T. ruralis, only the second published chloroplast genome for a moss, and the first for a vegetatively desiccation-tolerant plant. Results The Tortula chloroplast genome is ~123,500 bp, and differs in a number of ways from that of Physcomitrella patens, the first published moss chloroplast genome. For example, Tortula lacks the ~71 kb inversion found in the large single copy region of the Physcomitrella genome and other members of the Funariales. Also, the Tortula chloroplast genome lacks petN, a gene found in all known land plant plastid genomes. In addition, an unusual case of nucleotide polymorphism was discovered. Conclusions Although the chloroplast genome of Tortula ruralis differs from that of the only other sequenced moss, Physcomitrella patens, we have yet to determine the biological significance of the differences. The polymorphisms we have uncovered in the sequencing of the genome offer a rare possibility (for mosses of the generation of DNA markers for fine-level phylogenetic studies, or to investigate individual variation within populations.

  7. The complete chloroplast genome of banana (Musa acuminata, Zingiberales: insight into plastid monocotyledon evolution.

    Directory of Open Access Journals (Sweden)

    Guillaume Martin

    Full Text Available BACKGROUND: Banana (genus Musa is a crop of major economic importance worldwide. It is a monocotyledonous member of the Zingiberales, a sister group of the widely studied Poales. Most cultivated bananas are natural Musa inter-(sub-specific triploid hybrids. A Musa acuminata reference nuclear genome sequence was recently produced based on sequencing of genomic DNA enriched in nucleus. METHODOLOGY/PRINCIPAL FINDINGS: The Musa acuminata chloroplast genome was assembled with chloroplast reads extracted from whole-genome-shotgun sequence data. The Musa chloroplast genome is a circular molecule of 169,972 bp with a quadripartite structure containing two single copy regions, a Large Single Copy region (LSC, 88,338 bp and a Small Single Copy region (SSC, 10,768 bp separated by Inverted Repeat regions (IRs, 35,433 bp. Two forms of the chloroplast genome relative to the orientation of SSC versus LSC were found. The Musa chloroplast genome shows an extreme IR expansion at the IR/SSC boundary relative to the most common structures found in angiosperms. This expansion consists of the integration of three additional complete genes (rps15, ndhH and ycf1 and part of the ndhA gene. No such expansion has been observed in monocots so far. Simple Sequence Repeats were identified in the Musa chloroplast genome and a new set of Musa chloroplastic markers was designed. CONCLUSION: The complete sequence of M. acuminata ssp malaccensis chloroplast we reported here is the first one for the Zingiberales order. As such it provides new insight in the evolution of the chloroplast of monocotyledons. In particular, it reinforces that IR/SSC expansion has occurred independently several times within monocotyledons. The discovery of new polymorphic markers within Musa chloroplast opens new perspectives to better understand the origin of cultivated triploid bananas.

  8. Altered cytokinin metabolism affects cytokinin, auxin, and abscisic acid contents in leaves and chloroplasts, and chloroplast ultrastructure in transgenic tobacco

    Czech Academy of Sciences Publication Activity Database

    Polanská, Lenka; Vičánková, Anna; Nováková, Marie; Malbeck, Jiří; Dobrev, Petre; Brzobohatý, Břetislav; Vaňková, Radomíra; Macháčková, Ivana

    2007-01-01

    Roč. 58, č. 3 (2007), s. 637-649. ISSN 0022-0957 R&D Projects: GA ČR GA206/03/0369; GA ČR GA206/06/1306; GA AV ČR IAA600040612 Institutional research plan: CEZ:AV0Z50380511; CEZ:AV0Z50040507 Source of funding: V - iné verejné zdroje ; V - iné verejné zdroje Keywords : abscisic acid * auxin * chloroplast ultrastructure Subject RIV: EF - Botanics Impact factor: 3.917, year: 2007

  9. Ancestral sleep.

    Science.gov (United States)

    de la Iglesia, Horacio O; Moreno, Claudia; Lowden, Arne; Louzada, Fernando; Marqueze, Elaine; Levandovski, Rosa; Pilz, Luisa K; Valeggia, Claudia; Fernandez-Duque, Eduardo; Golombek, Diego A; Czeisler, Charles A; Skene, Debra J; Duffy, Jeanne F; Roenneberg, Till

    2016-04-01

    While we do not yet understand all the functions of sleep, its critical role for normal physiology and behaviour is evident. Its amount and temporal pattern depend on species and condition. Humans sleep about a third of the day with the longest, consolidated episode during the night. The change in lifestyle from hunter-gatherers via agricultural communities to densely populated industrialized centres has certainly affected sleep, and a major concern in the medical community is the impact of insufficient sleep on health [1,2]. One of the causal mechanisms leading to insufficient sleep is altered exposure to the natural light-dark cycle. This includes the wide availability of electric light, attenuated exposure to daylight within buildings, and evening use of light-emitting devices, all of which decrease the strength of natural light-dark signals that entrain circadian systems [3]. PMID:27046809

  10. The complete chloroplast genome of Cinnamomum kanehirae Hayata (Lauraceae).

    Science.gov (United States)

    Wu, Chia-Chen; Ho, Cheng-Kuen; Chang, Shu-Hwa

    2016-07-01

    The complete chloroplast genome of Cinnamomum kanehirae (Hayata), the first to be completely sequenced of Lauraceae family, is presented in this study. The total genome size is 152,700 bp, with a typical circular structure including a pair of inverted repeats (IRa/b) of 20,107 bp of length separated by a large single-copy region (LSC) and a small single-copy region (SSC) of 93,642 bp and 18,844 bp of length, respectively. The overall GC content of the genome is 39.1%. The nucleotide sequence shows 91% identities with Liriodendron tulipifera in the Magnoliaceae. In total, 123 annotated genes consisted of 79 coding genes, eight rRNA genes, and 36 tRNA genes. Among all 79 coding genes, seven genes (rpoC1, atpF, rpl2, ndhB, ndhA, rps16, and rpl2) contain one intron, while two genes (ycf3 and clpP) contain two introns. The maximum likelihood phylogenetic analysis revealed that C. kanehirae chloroplast genome is closely related to Calycanthus fertilis within Laurales order. PMID:26053940

  11. Chloroplast protein synthesis: thylakoid bound polysomes synthesize thylakoid proteins

    International Nuclear Information System (INIS)

    Previous work indicated more polysomes bound to pea thylakoids in light than in the dark, in vivo. With isolated intact chloroplasts incubated in darkness, 24 to 74% more RNA was thylakoid-bound at pH 8.3 than at pH 7. Thus the major effect of light in vivo may be due to higher stroma pH. In isolated pea chloroplasts, initiation inhibitors (pactamycin and kanamycin) decreased the extent of RNA binding, and elongation inhibitors (lincomycin and streptomycin) increased it. Thus translation initiation and termination probably control the cycling of bound ribosomes. While only 3 to 6% of total RNA is in bound polysomes the incorporation of 3H-Leu into thylakoids was proportional to the amount of this bound RNA. When Micrococcal nuclease-treated thylakoids were added to labeled runoff translation products of stroma ribosomes, less than 1% of the label adhered to the added membranes; but 37% of the labeled products made by thylakoid polysomes were bound. These data support the concept that stroma ribosomes are recruited into thylakoid proteins

  12. The molecular architecture of the chloroplast thylakoid membrane

    Energy Technology Data Exchange (ETDEWEB)

    Stefansson, H.

    1996-08-01

    Non-detergent procedure for isolation of sub-thylakoid vesicle populations derived from different structural domains of the chloroplast thylakoid membrane has been developed. Sub-thylakoid vesicles representing the grana, grana core, stroma lamellae, and the grana margins have been isolated and their protein composition has been investigated. Furthermore a novel non-detergent procedure for investigating the pigment composition of photosynthetic complexes located in the different structural domains has been developed. This procedure circumvents selective extractions, an perturbing effect often combined with detergent isolations of membrane bound protein complexes. The fractionation experiments show that the NADPH dehydrogenase, suggested to operate as NADPH or ferredoxin-plastoquinone oxidoreductase in cyclic electron transport around photosystem I, is stoichiometrically depleted on photosystem I basis in the grana domain. The fractionation studies are consistent with the model of the thylakoid membrane where the photosystems in the grana are operating in a linear electron transport whereas the site of cyclic electron transport is in the stroma lamellae. It is suggested that partial destacking of grana, as a result of light-induced protein phosphorylation, may promote the exposure of the granal photosystem I centers to the chloroplast stroma and thereby enhance their participation in cyclic electron transport activity. 146 refs, 18 figs

  13. Chloroplast FBPase and SBPase are thioredoxin-linked enzymes with similar architecture but different evolutionary histories.

    Science.gov (United States)

    Gütle, Desirée D; Roret, Thomas; Müller, Stefanie J; Couturier, Jérémy; Lemaire, Stéphane D; Hecker, Arnaud; Dhalleine, Tiphaine; Buchanan, Bob B; Reski, Ralf; Einsle, Oliver; Jacquot, Jean-Pierre

    2016-06-14

    The Calvin-Benson cycle of carbon dioxide fixation in chloroplasts is controlled by light-dependent redox reactions that target specific enzymes. Of the regulatory members of the cycle, our knowledge of sedoheptulose-1,7-bisphosphatase (SBPase) is particularly scanty, despite growing evidence for its importance and link to plant productivity. To help fill this gap, we have purified, crystallized, and characterized the recombinant form of the enzyme together with the better studied fructose-1,6-bisphosphatase (FBPase), in both cases from the moss Physcomitrella patens (Pp). Overall, the moss enzymes resembled their counterparts from seed plants, including oligomeric organization-PpSBPase is a dimer, and PpFBPase is a tetramer. The two phosphatases showed striking structural homology to each other, differing primarily in their solvent-exposed surface areas in a manner accounting for their specificity for seven-carbon (sedoheptulose) and six-carbon (fructose) sugar bisphosphate substrates. The two enzymes had a similar redox potential for their regulatory redox-active disulfides (-310 mV for PpSBPase vs. -290 mV for PpFBPase), requirement for Mg(2+) and thioredoxin (TRX) specificity (TRX f > TRX m). Previously known to differ in the position and sequence of their regulatory cysteines, the enzymes unexpectedly showed unique evolutionary histories. The FBPase gene originated in bacteria in conjunction with the endosymbiotic event giving rise to mitochondria, whereas SBPase arose from an archaeal gene resident in the eukaryotic host. These findings raise the question of how enzymes with such different evolutionary origins achieved structural similarity and adapted to control by the same light-dependent photosynthetic mechanism-namely ferredoxin, ferredoxin-thioredoxin reductase, and thioredoxin. PMID:27226308

  14. A high-throughput method for detection of DNA in chloroplasts using flow cytometry

    Directory of Open Access Journals (Sweden)

    Oldenburg Delene J

    2007-03-01

    Full Text Available Abstract Background The amount of DNA in the chloroplasts of some plant species has been shown recently to decline dramatically during leaf development. A high-throughput method of DNA detection in chloroplasts is now needed in order to facilitate the further investigation of this process using large numbers of tissue samples. Results The DNA-binding fluorophores 4',6-diamidino-2-phenylindole (DAPI, SYBR Green I (SG, SYTO 42, and SYTO 45 were assessed for their utility in flow cytometric analysis of DNA in Arabidopsis chloroplasts. Fluorescence microscopy and real-time quantitative PCR (qPCR were used to validate flow cytometry data. We found neither DAPI nor SYTO 45 suitable for flow cytometric analysis of chloroplast DNA (cpDNA content, but did find changes in cpDNA content during development by flow cytometry using SG and SYTO 42. The latter dye provided more sensitive detection, and the results were similar to those from the fluorescence microscopic analysis. Differences in SYTO 42 fluorescence were found to correlate with differences in cpDNA content as determined by qPCR using three primer sets widely spaced across the chloroplast genome, suggesting that the whole genome undergoes copy number reduction during development, rather than selective reduction/degradation of subgenomic regions. Conclusion Flow cytometric analysis of chloroplasts stained with SYTO 42 is a high-throughput method suitable for determining changes in cpDNA content during development and for sorting chloroplasts on the basis of DNA content.

  15. A multiple-method approach reveals a declining amount of chloroplast DNA during development in Arabidopsis

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    Oldenburg Delene J

    2009-01-01

    Full Text Available Abstract Background A decline in chloroplast DNA (cpDNA during leaf maturity has been reported previously for eight plant species, including Arabidopsis thaliana. Recent studies, however, concluded that the amount of cpDNA during leaf development in Arabidopsis remained constant. Results To evaluate alternative hypotheses for these two contradictory observations, we examined cpDNA in Arabidopsis shoot tissues at different times during development using several methods: staining leaf sections as well as individual isolated chloroplasts with 4',6-diamidino-2-phenylindole (DAPI, real-time quantitative PCR with DNA prepared from total tissue as well as from isolated chloroplasts, fluorescence microscopy of ethidium-stained DNA molecules prepared in gel from isolated plastids, and blot-hybridization of restriction-digested total tissue DNA. We observed a developmental decline of about two- to three-fold in mean DNA per chloroplast and two- to five-fold in the fraction of cellular DNA represented by chloroplast DNA. Conclusion Since the two- to five-fold reduction in cpDNA content could not be attributed to an artifact of chloroplast isolation, we conclude that DNA within Arabidopsis chloroplasts is degraded in vivo as leaves mature.

  16. The Chloroplast Outer Envelope Membrane: The Edge of Light and Excitement

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The chloroplast is surrounded by a double-membrane envelope at which proteins, ions, and numerous metabolites Including nucleotides, amino acids, fatty acids, and carbohydrates are exchanged between the two aqueous phases, the cytoplasm and the chloroplast stroma. The chloroplast envelope is also the location where the biosynthesis and accumulation of various lipids take place. By contrast to the inner membrane, which contains a number of specific transporters and acts as the permeability barrier, the chloroplast outer membrane has often been considered a passive compartment derived from the phagosomal membrane. However, the presence of galactoglycerolipids and β-barrel membrane proteins support the common origin of the outer membranes of the chloroplast envelope and extant cyanobacteria. Furthermore, recent progress in the field underlines that the chloroplast outer envelope plays important roles not only for translocation of various molecules, but also for regulation of metabolic activities and signaling processes. The chloroplast outer envelope membrane offers various interesting and challenging questions that are relevant to the understanding of organelle biogenesis, plant growth and development, and also membrane biology in general.

  17. Is Chloroplast Movement in Tobacco Plants Influenced Systemically after Local Illumination or Burning Stress?

    Institute of Scientific and Technical Information of China (English)

    Jan Naus; Monika Rolencova; Vladimira Hlavackova

    2008-01-01

    Chloroplast movement has been studied In many plants mainly in relation to the local light, mechanical or stress effects. Here we investigated possible systemic responses of chloroplast movement to local light or burning stress in tobacco plants (Nicotiana tabacum cv. Samsun). Chloroplast movement was measured using two independent methods: one with a SPAD 502 Chlorophyll meter and another by collimated transmittance at a selected wavelength (676 nm). A sensitive pedodic movement of chloroplasts was used in high or low (2 000 or 50 μmol/m2 per s photosynthetically active radiation, respectively) cold white light with periods of 50 or 130 min. Measurements were carried out in the irradiated area, in the non-irradiated area of the same leaf or in the leaf located on the stem below the irradiated or burned one. No significant changes in systemic chloroplast movement in non-irradiated parts of the leaf and in the non-treated leaf were detected. Our data indicate that chloroplast movement in tobacco is dependent dominantly on the intensity and spectral composition of the incident light and on the local stimulation and state of the target tissue. No systemic signal was strong enough tovoke a detectable systemic response in chloroplast movement in distant untreated tissues of tobacco plants.

  18. The chloroplast genome of a symbiodinium sp. clade C3 isolate

    KAUST Repository

    Barbrook, Adrian C.

    2014-01-01

    Dinoflagellate algae of the genus Symbiodinium form important symbioses within corals and other benthic marine animals. Dinoflagellates possess an extremely reduced plastid genome relative to those examined in plants and other algae. In dinoflagellates the plastid genes are located on small plasmids, commonly referred to as \\'minicircles\\'. However, the chloroplast genomes of dinoflagellates have only been extensively characterised from a handful of species. There is also evidence of considerable variation in the chloroplast genome organisation across those species that have been examined. We therefore characterised the chloroplast genome from an environmental coral isolate, in this case containing a symbiont belonging to the Symbiodinium sp. clade C3. The gene content of the genome is well conserved with respect to previously characterised genomes. However, unlike previously characterised dinoflagellate chloroplast genomes we did not identify any \\'empty\\' minicircles. The sequences of this chloroplast genome show a high rate of evolution relative to other algal species. Particularly notable was a surprisingly high level of sequence divergence within the core polypeptides of photosystem I, the reasons for which are currently unknown. This chloroplast genome also possesses distinctive codon usage and GC content. These features suggest that chloroplast genomes in Symbiodinium are highly plastic. © 2013 Adrian C. Barbrook.

  19. Transcriptome analysis of ectopic chloroplast development in green curd cauliflower (Brassica oleracea L. var. botrytis

    Directory of Open Access Journals (Sweden)

    Zhou Xiangjun

    2011-11-01

    Full Text Available Abstract Background Chloroplasts are the green plastids where photosynthesis takes place. The biogenesis of chloroplasts requires the coordinate expression of both nuclear and chloroplast genes and is regulated by developmental and environmental signals. Despite extensive studies of this process, the genetic basis and the regulatory control of chloroplast biogenesis and development remain to be elucidated. Results Green cauliflower mutant causes ectopic development of chloroplasts in the curd tissue of the plant, turning the otherwise white curd green. To investigate the transcriptional control of chloroplast development, we compared gene expression between green and white curds using the RNA-seq approach. Deep sequencing produced over 15 million reads with lengths of 86 base pairs from each cDNA library. A total of 7,155 genes were found to exhibit at least 3-fold changes in expression between green and white curds. These included light-regulated genes, genes encoding chloroplast constituents, and genes involved in chlorophyll biosynthesis. Moreover, we discovered that the cauliflower ELONGATED HYPOCOTYL5 (BoHY5 was expressed higher in green curds than white curds and that 2616 HY5-targeted genes, including 1600 up-regulated genes and 1016 down-regulated genes, were differently expressed in green in comparison to white curd tissue. All these 1600 up-regulated genes were HY5-targeted genes in the light. Conclusions The genome-wide profiling of gene expression by RNA-seq in green curds led to the identification of large numbers of genes associated with chloroplast development, and suggested the role of regulatory genes in the high hierarchy of light signaling pathways in mediating the ectopic chloroplast development in the green curd cauliflower mutant.

  20. Cloning and expression analysis of the chloroplast fructose-1,6-bisphosphatase gene from Pyropia haitanensis

    Institute of Scientific and Technical Information of China (English)

    XIAO Haidong; CHEN Changsheng; XU Yan; JI Dehua; XIE Chaotian

    2014-01-01

    Fructose-1,6-bisphosphatase (FBPase) is one of the key enzymes in Calvin circle and starch biosynthesis. In this study, the full-length of cpFBPase gene from Pyropia haitanensis was cloned by using rapid amplifica-tion of cDNA ends (RACE) technology. The nucleotide sequence of PhcpFBPase consists of 1 400 bp, includ-ing a 5′untranslated region (UTR) of 92 bp, a 3′ UTR of 69 bp, and an open reading frame (ORF) of 1 236 bp, which can be translated into a 412-amino-acid putative peptides with a molecular weight of 44.3 kDa and a theoretical pI of 5.23. Multiple sequence alignment indicated that the protein belonged to the chloroplast FBPase enzyme. Phylogenetic analysis showed that the protein assembled with the cpFBPase of a thermal tolerant unicellular red micro-algae Galdieria sulphuraria. Expression patterns analyzed by qRT-PCR re-vealed that the expression of PhcpFBPase gene in the thallus phage was 7-fold higher than in the conchocelis phage, which suggested the different mechanisms of inorganic carbon utilization among the different life phages of P. haitanensis. And the different response modes of PhcpFBPase mRNA levels to high temperature and desiccation stress indicated that PhcpFBPase played an important role in responsing to abiotic stress.

  1. Acquired phototrophy through retention of functional chloroplasts increases growth efficiency of the sea slug Elysia viridis.

    Directory of Open Access Journals (Sweden)

    Finn A Baumgartner

    Full Text Available Photosynthesis is a fundamental process sustaining heterotrophic organisms at all trophic levels. Some mixotrophs can retain functional chloroplasts from food (kleptoplasty, and it is hypothesized that carbon acquired through kleptoplasty may enhance trophic energy transfer through increased host growth efficiency. Sacoglossan sea slugs are the only known metazoans capable of kleptoplasty, but the relative fitness contributions of heterotrophy through grazing, and phototrophy via kleptoplasts, are not well understood. Fitness benefits (i.e. increased survival or growth of kleptoplasty in sacoglossans are commonly studied in ecologically unrealistic conditions under extended periods of complete darkness and/or starvation. We compared the growth efficiency of the sacoglossan Elysia viridis with access to algal diets providing kleptoplasts of differing functionality under ecologically relevant light conditions. Individuals fed Codium fragile, which provide highly functional kleptoplasts, nearly doubled their growth efficiency under high compared to low light. In contrast, individuals fed Cladophora rupestris, which provided kleptoplasts of limited functionality, showed no difference in growth efficiency between light treatments. Slugs feeding on Codium, but not on Cladophora, showed higher relative electron transport rates (rETR in high compared to low light. Furthermore, there were no differences in the consumption rates of the slugs between different light treatments, and only small differences in nutritional traits of algal diets, indicating that the increased growth efficiency of E. viridis feeding on Codium was due to retention of functional kleptoplasts. Our results show that functional kleptoplasts from Codium can provide sacoglossan sea slugs with fitness advantages through photosynthesis.

  2. Structure and transcription of the spinach chloroplast rDNA leader region.

    OpenAIRE

    Briat, J F; Dron, M; Loiseaux, S; Mache, R

    1982-01-01

    A cloned fragment of spinach chloroplast DNA carrying 140 bp of the 16S rRNA gene and 691 bp upstream this gene has been analysed by DNA sequencing, by in vitro transcription, by S1 mapping with chloroplast RNAs and purified 16S rRNA from 30S ribosomal subunits. A tRNAVal gene has been located between the position 394 and 465. Crude chloroplast RNA polymerase has been purified by heparin sepharose chromatography of a 80 000 g supernatant from pure lysed spinach plastids and used to transcribe...

  3. Neanderthal and Denisova genetic affinities with contemporary humans: introgression versus common ancestral polymorphisms.

    Science.gov (United States)

    Lowery, Robert K; Uribe, Gabriel; Jimenez, Eric B; Weiss, Mark A; Herrera, Kristian J; Regueiro, Maria; Herrera, Rene J

    2013-11-01

    Analyses of the genetic relationships among modern humans, Neanderthals and Denisovans have suggested that 1-4% of the non-Sub-Saharan African gene pool may be Neanderthal derived, while 6-8% of the Melanesian gene pool may be the product of admixture between the Denisovans and the direct ancestors of Melanesians. In the present study, we analyzed single nucleotide polymorphism (SNP) diversity among a worldwide collection of contemporary human populations with respect to the genetic constitution of these two archaic hominins and Pan troglodytes (chimpanzee). We partitioned SNPs into subsets, including those that are derived in both archaic lineages, those that are ancestral in both archaic lineages and those that are only derived in one archaic lineage. By doing this, we have conducted separate examinations of subsets of mutations with higher probabilities of divergent phylogenetic origins. While previous investigations have excluded SNPs from common ancestors in principal component analyses, we included common ancestral SNPs in our analyses to visualize the relative placement of the Neanderthal and Denisova among human populations. To assess the genetic similarities among the various hominin lineages, we performed genetic structure analyses to provide a comparison of genetic patterns found within contemporary human genomes that may have archaic or common ancestral roots. Our results indicate that 3.6% of the Neanderthal genome is shared with roughly 65.4% of the average European gene pool, which clinally diminishes with distance from Europe. Our results suggest that Neanderthal genetic associations with contemporary non-Sub-Saharan African populations, as well as the genetic affinities observed between Denisovans and Melanesians most likely result from the retention of ancient mutations in these populations. PMID:23872234

  4. Chromosome painting in three-toed sloths: a cytogenetic signature and ancestral karyotype for Xenarthra

    Directory of Open Access Journals (Sweden)

    Azevedo Nathália F

    2012-03-01

    Full Text Available Abstract Background Xenarthra (sloths, armadillos and anteaters represent one of four currently recognized Eutherian mammal supraorders. Some phylogenomic studies point to the possibility of Xenarthra being at the base of the Eutherian tree, together or not with the supraorder Afrotheria. We performed painting with human autosomes and X-chromosome specific probes on metaphases of two three-toed sloths: Bradypus torquatus and B. variegatus. These species represent the fourth of the five extant Xenarthra families to be studied with this approach. Results Eleven human chromosomes were conserved as one block in both B. torquatus and B. variegatus: (HSA 5, 6, 9, 11, 13, 14, 15, 17, 18, 20, 21 and the X chromosome. B. torquatus, three additional human chromosomes were conserved intact (HSA 1, 3 and 4. The remaining human chromosomes were represented by two or three segments on each sloth. Seven associations between human chromosomes were detected in the karyotypes of both B. torquatus and B. variegatus: HSA 3/21, 4/8, 7/10, 7/16, 12/22, 14/15 and 17/19. The ancestral Eutherian association 16/19 was not detected in the Bradypus species. Conclusions Our results together with previous reports enabled us to propose a hypothetical ancestral Xenarthran karyotype with 48 chromosomes that would differ from the proposed ancestral Eutherian karyotype by the presence of the association HSA 7/10 and by the split of HSA 8 into three blocks, instead of the two found in the Eutherian ancestor. These same chromosome features point to the monophyly of Xenarthra, making this the second supraorder of placental mammals to have a chromosome signature supporting its monophyly.

  5. Chromosome painting in three-toed sloths: a cytogenetic signature and ancestral karyotype for Xenarthra

    Science.gov (United States)

    2012-01-01

    Background Xenarthra (sloths, armadillos and anteaters) represent one of four currently recognized Eutherian mammal supraorders. Some phylogenomic studies point to the possibility of Xenarthra being at the base of the Eutherian tree, together or not with the supraorder Afrotheria. We performed painting with human autosomes and X-chromosome specific probes on metaphases of two three-toed sloths: Bradypus torquatus and B. variegatus. These species represent the fourth of the five extant Xenarthra families to be studied with this approach. Results Eleven human chromosomes were conserved as one block in both B. torquatus and B. variegatus: (HSA 5, 6, 9, 11, 13, 14, 15, 17, 18, 20, 21 and the X chromosome). B. torquatus, three additional human chromosomes were conserved intact (HSA 1, 3 and 4). The remaining human chromosomes were represented by two or three segments on each sloth. Seven associations between human chromosomes were detected in the karyotypes of both B. torquatus and B. variegatus: HSA 3/21, 4/8, 7/10, 7/16, 12/22, 14/15 and 17/19. The ancestral Eutherian association 16/19 was not detected in the Bradypus species. Conclusions Our results together with previous reports enabled us to propose a hypothetical ancestral Xenarthran karyotype with 48 chromosomes that would differ from the proposed ancestral Eutherian karyotype by the presence of the association HSA 7/10 and by the split of HSA 8 into three blocks, instead of the two found in the Eutherian ancestor. These same chromosome features point to the monophyly of Xenarthra, making this the second supraorder of placental mammals to have a chromosome signature supporting its monophyly. PMID:22429690

  6. Ancestral polymorphism and recent invasion of transposable elements in Drosophila species

    Directory of Open Access Journals (Sweden)

    Dias Elaine

    2012-07-01

    Full Text Available Abstract Background During the evolution of transposable elements, some processes, such as ancestral polymorphisms and horizontal transfer of sequences between species, can produce incongruences in phylogenies. We investigated the evolutionary history of the transposable elements Bari and 412 in the sequenced genomes of the Drosophila melanogaster group and in the sibling species D. melanogaster and D. simulans using traditional phylogenetic and network approaches. Results Maximum likelihood (ML phylogenetic analyses revealed incongruences and unresolved relationships for both the Bari and 412 elements. The DNA transposon Bari within the D. ananassae genome is more closely related to the element of the melanogaster complex than to the sequence in D. erecta, which is inconsistent with the species phylogeny. Divergence analysis and the comparison of the rate of synonymous substitutions per synonymous site of the Bari and host gene sequences explain the incongruence as an ancestral polymorphism that was inherited stochastically by the derived species. Unresolved relationships were observed in the ML phylogeny of both elements involving D. melanogaster, D. simulans and D. sechellia. A network approach was used to attempt to resolve these relationships. The resulting tree suggests recent transfers of both elements between D. melanogaster and D. simulans. The divergence values of the elements between these species support this conclusion. Conclusions We showed that ancestral polymorphism and recent invasion of genomes due to introgression or horizontal transfer between species occurred during the evolutionary history of the Bari and 412 elements in the melanogaster group. These invasions likely occurred in Africa during the Pleistocene, before the worldwide expansion of D. melanogaster and D. simulans.

  7. The mitochondrial genome structure of Xenoturbella bocki (phylum Xenoturbellida is ancestral within the deuterostomes

    Directory of Open Access Journals (Sweden)

    Lanfear Robert

    2009-05-01

    Full Text Available Abstract Background Mitochondrial genome comparisons contribute in multiple ways when inferring animal relationships. As well as primary sequence data, rare genomic changes such as gene order, shared gene boundaries and genetic code changes, which are unlikely to have arisen through convergent evolution, are useful tools in resolving deep phylogenies. Xenoturbella bocki is a morphologically simple benthic marine worm recently found to belong among the deuterostomes. Here we present analyses comparing the Xenoturbella bocki mitochondrial gene order, genetic code and control region to those of other metazoan groups. Results The complete mitochondrial genome sequence of Xenoturbella bocki was determined. The gene order is most similar to that of the chordates and the hemichordates, indicating that this conserved mitochondrial gene order might be ancestral to the deuterostome clade. Using data from all phyla of deuterostomes, we infer the ancestral mitochondrial gene order for this clade. Using inversion and breakpoint analyses of metazoan mitochondrial genomes, we test conflicting hypotheses for the phylogenetic placement of Xenoturbella and find a closer affinity to the hemichordates than to other metazoan groups. Comparative analyses of the control region reveal similarities in the transcription initiation and termination sites and origin of replication of Xenoturbella with those of the vertebrates. Phylogenetic analyses of the mitochondrial sequence indicate a weakly supported placement as a basal deuterostome, a result that may be the effect of compositional bias. Conclusion The mitochondrial genome of Xenoturbella bocki has a very conserved gene arrangement in the deuterostome group, strikingly similar to that of the hemichordates and the chordates, and thus to the ancestral deuterostome gene order. Similarity to the hemichordates in particular is suggested by inversion and breakpoint analysis. Finally, while phylogenetic analyses of the

  8. Contrasting determinants of abundance in ancestral and colonized ranges of an invasive brood parasite

    Science.gov (United States)

    Hahn, D.C.; O'Connor, R.J.

    2002-01-01

    Avian species distributions are typically regarded as constrained by spatially extensive variables such as climate, habitat, spatial patchiness, and microhabitat attributes. We hypothesized that the distribution of a brood parasite depends as strongly on host distribution patterns as on biophysical factors and examined this hypothesis with respect to the national distribution of the Brown-headed Cowbird (Molothrus ater). We applied a classification and regression (CART) analysis to data from the Breeding Bird Survey (BBS) and the Christmas Bird Count (CBC) and derived hierarchically organized statistical models of the influence of climate and weather, cropping and land use, and host abundance and distribution on the distribution of the Brown-headed Cowbird within the conterminous United States. The model accounted for 47.2% of the variation in cowbird incidence, and host abundance was the top predictor with an R2 of 18.9%. The other predictors identified by the model (crops 15.7%, weather and climate 14.3%, and region 9.6%) fit the ecological profile of this cowbird. We showed that host abundance was independent of these environmental predictors of cowbird distribution. At the regional scale host abundance played a very strong role in determining cowbird abundance in the cowbird?s colonized range east and west of their ancestral range in the Great Plains (26.6%). Crops were not a major predictor for cowbirds in their ancestral range, although they are the most important predictive factor (33%) for the grassland passerines that are the cowbird?s ancestral hosts. Consequently our findings suggest that the distribution of hosts does indeed take precedence over habitat attributes in shaping the cowbird?s distribution at a national scale, within an envelope of constraint set by biophysical factors.

  9. Analysis of Ancestral and Functionally Relevant CD5 Variants in Systemic Lupus Erythematosus Patients

    OpenAIRE

    Maria Carmen Cenit; Mario Martínez-Florensa; Marta Consuegra; Lizette Bonet; Elena Carnero-Montoro; Noelia Armiger; Miguel Caballero-Baños; Maria Teresa Arias; Daniel Benitez; Norberto Ortego-Centeno; Enrique de Ramón; José Mario Sabio; García-Hernández, Francisco J; Carles Tolosa; Ana Suárez

    2014-01-01

    Objective: CD5 plays a crucial role in autoimmunity and is a well-established genetic risk factor of developing RA. Recently, evidence of positive selection has been provided for the CD5 Pro224-Val471 haplotype in East Asian populations. The aim of the present work was to further analyze the functional relevance of non-synonymous CD5 polymorphisms conforming the ancestral and the newly derived haplotypes (Pro224-Ala471 and Pro224-Val471, respectively) as well as to investigate the potential r...

  10. Ancestral heritage saves tribes during 1 April 2007 Solomon Islands tsunami

    Science.gov (United States)

    Fritz, Hermann M.; Kalligeris, Nikos

    2008-01-01

    The 1 April 2007 magnitude Ms 8.1 earthquake off the New Georgia Group in the Solomon Islands generated a tsunami that killed 52 with locally focused run-up heights of 12 m, local flow depths of 5 m as well as tectonic uplift up to 3.6 m and subsidence down to -1.5 m. A reconnaissance team deployed within one week investigated 65 coastal settlements on 13 remote Islands. The ancestral heritage ``run to high ground after an earthquake'' passed on to younger generations by survivors of smaller historic tsunamis triggered an immediate spontaneous self evacuation containing the death toll.

  11. The complete chloroplast genome sequence of Anoectochilus emeiensis.

    Science.gov (United States)

    Zhu, Shuying; Niu, Zhitao; Yan, Wenjin; Xue, Qingyun; Ding, Xiaoyu

    2016-09-01

    The complete chloroplast (cp) genome sequence of Anoectochilus emeiensis, an extremely endangered medical plant with important economic value, was determined and characterized. The genome size was 152 650 bp, containing a pair of inverted repeats (IRs) (26 319 bp) which were separated by a large single copy (LSC) (82 670 bp) and a small single copy (SSC) (17 342 bp). The cpDNA of A. emeiensis contained 113 unique genes, including 79 protein coding genes, 30 tRNA genes and 4 rRNA genes. Among them, 18 genes contained one or two introns. The overall AT content of the genome was 63.1%. PMID:26403535

  12. Functional analysis of chloroplast early light inducible proteins (ELIPs)

    Energy Technology Data Exchange (ETDEWEB)

    Wetzel, Carolyn M

    2005-02-22

    The objectives of this project were to characterize gene expression patterns of early light inducible protein (ELIP) genes in Arabidopsis thaliana and in Lycopersicon esculentum, to identify knock mutants of the 2 ELIP genes in Arabidopsis, and to characterize the effects of the knockouts. Expression in Arabidopsis was studied in response to thylakoid electron transport chain (PETC) capacity, where it was found that there is a signal for expression associated with reduction of the PETC. Expression in response to salt was also studied, with different responses of the two gene copies. Knockout lines for ELIP1 and ELIP2 have been identified and are being characterized. In tomato, it was found that the single-copy ELIP gene is highly expressed in ripening fruit during the chloroplast-to-chromoplast transition. Studies of expression in tomato ripening mutants are ongoing.

  13. The complete chloroplast genome sequence of Euonymus japonicus (Celastraceae).

    Science.gov (United States)

    Choi, Kyoung Su; Park, SeonJoo

    2016-09-01

    The complete chloroplast (cp) genome sequence of the Euonymus japonicus, the first sequenced of the genus Euonymus, was reported in this study. The total length was 157 637 bp, containing a pair of 26 678 bp inverted repeat region (IR), which were separated by small single copy (SSC) region and large single copy (LSC) region of 18 340 bp and 85 941 bp, respectively. This genome contains 107 unique genes, including 74 coding genes, four rRNA genes, and 29 tRNA genes. Seventeen genes contain intron of E. japonicus, of which three genes (clpP, ycf3, and rps12) include two introns. The maximum likelihood (ML) phylogenetic analysis revealed that E. japonicus was closely related to Manihot and Populus. PMID:26407184

  14. The complete chloroplast genomes of Cannabis sativa and Humulus lupulus.

    Science.gov (United States)

    Vergara, Daniela; White, Kristin H; Keepers, Kyle G; Kane, Nolan C

    2016-09-01

    Cannabis and Humulus are sister genera comprising the entirety of the Cannabaceae sensu stricto, including C. sativa L. (marijuana, hemp), and H. lupulus L. (hops) as two economically important crops. These two plants have been used by humans for many purposes including as a fiber, food, medicine, or inebriant in the case of C. sativa, and as a flavoring component in beer brewing in the case of H. lupulus. In this study, we report the complete chloroplast genomes for two distinct hemp varieties of C. sativa, Italian "Carmagnola" and Russian "Dagestani", and one Czech variety of H. lupulus "Saazer". Both C. sativa genomes are 153 871 bp in length, while the H. lupulus genome is 153 751 bp. The genomes from the two C. sativa varieties differ in 16 single nucleotide polymorphisms (SNPs), while the H. lupulus genome differs in 1722 SNPs from both C. sativa cultivars. PMID:26329384

  15. The whole chloroplast genomes of two Eutrema species (Brassicaceae).

    Science.gov (United States)

    Hao, Guoqian; Bi, Hao; Li, Yuanshuo; He, Qi; Ma, Yazhen; Guo, Xinyi; Ma, Tao

    2016-09-01

    In this study, we determined the complete chloroplast genomes from two crucifer species of the Eutrema genus. The sizes of the two cp genomes were 153 948 bp (E. yunnanense) and 153 876 bp (E. heterophyllum). Both genomes have the typical quadripartite structure consisting of a large single copy region, a small single copy region and two inverted repeats. Gene contents and their relative positions of the 132 individual genes (87 protein-coding genes, eight rRNA, and 37 tRNA genes) of either genome were identical to each other. Phylogenetic analysis supports the idea that the currently recognized Eutrema genus is monophyletic and that E. salsugineum and Schrenkiella parvula evolved salt tolerance independently. PMID:26329763

  16. Protein phosphorylation in chloroplasts - a survey of phosphorylation targets.

    Science.gov (United States)

    Baginsky, Sacha

    2016-06-01

    The development of new software tools, improved mass spectrometry equipment, a suite of optimized scan types, and better-quality phosphopeptide affinity capture have paved the way for an explosion of mass spectrometry data on phosphopeptides. Because phosphoproteomics achieves good sensitivity, most studies use complete cell extracts for phosphopeptide enrichment and identification without prior enrichment of proteins or subcellular compartments. As a consequence, the phosphoproteome of cell organelles often comes as a by-product from large-scale studies and is commonly assembled from these in meta-analyses. This review aims at providing some guidance on the limitations of meta-analyses that combine data from analyses with different scopes, reports on the current status of knowledge on chloroplast phosphorylation targets, provides initial insights into phosphorylation site conservation in different plant species, and highlights emerging information on the integration of gene expression with metabolism and photosynthesis by means of protein phosphorylation. PMID:26969742

  17. [Study of Chloroplast DNA Polymorphism in the Sunflower (Helianthus L.)].

    Science.gov (United States)

    Markina, N V; Usatov, A V; Logacheva, M D; Azarin, K V; Gorbachenko, C F; Kornienko, I V; Gavrilova, V A; Tihobaeva, V E

    2015-08-01

    The polymorphism of microsatellite loci of chloroplast genome in six Helianthus species and 46 lines of cultivated sunflower H. annuus (17 CMS lines and 29 Rf-lines) were studied. The differences between species are confined to four SSR loci. Within cultivated forms of the sunflower H. annuus, the polymorphism is absent. A comparative analysis was performed on sequences of the cpDNA inbred line 3629, line 398941 of the wild sunflower, and the American line HA383 H. annuus. As a result, 52 polymorphic loci represented by 27 SSR and 25 SNP were found; they can be used for genotyping of H. annuus samples, including cultural varieties: twelve polymorphic positions, of which eight are SSR and four are SNP. PMID:26601486

  18. Consistency and inconsistency of consensus methods for inferring species trees from gene trees in the presence of ancestral population structure.

    Science.gov (United States)

    DeGiorgio, Michael; Rosenberg, Noah A

    2016-08-01

    In the last few years, several statistically consistent consensus methods for species tree inference have been devised that are robust to the gene tree discordance caused by incomplete lineage sorting in unstructured ancestral populations. One source of gene tree discordance that has only recently been identified as a potential obstacle for phylogenetic inference is ancestral population structure. In this article, we describe a general model of ancestral population structure, and by relying on a single carefully constructed example scenario, we show that the consensus methods Democratic Vote, STEAC, STAR, R(∗) Consensus, Rooted Triple Consensus, Minimize Deep Coalescences, and Majority-Rule Consensus are statistically inconsistent under the model. We find that among the consensus methods evaluated, the only method that is statistically consistent in the presence of ancestral population structure is GLASS/Maximum Tree. We use simulations to evaluate the behavior of the various consensus methods in a model with ancestral population structure, showing that as the number of gene trees increases, estimates on the basis of GLASS/Maximum Tree approach the true species tree topology irrespective of the level of population structure, whereas estimates based on the remaining methods only approach the true species tree topology if the level of structure is low. However, through simulations using species trees both with and without ancestral population structure, we show that GLASS/Maximum Tree performs unusually poorly on gene trees inferred from alignments with little information. This practical limitation of GLASS/Maximum Tree together with the inconsistency of other methods prompts the need for both further testing of additional existing methods and development of novel methods under conditions that incorporate ancestral population structure. PMID:27086043

  19. Arabidopsis thaliana DNA gyrase is targeted to chloroplasts and mitochondria

    Science.gov (United States)

    Wall, Melisa K.; Mitchenall, Lesley A.; Maxwell, Anthony

    2004-01-01

    DNA gyrase is the bacterial DNA topoisomerase (topo) that supercoils DNA by using the free energy of ATP hydrolysis. The enzyme, an A2B2 tetramer encoded by the gyrA and gyrB genes, catalyses topological changes in DNA during replication and transcription, and is the only topo that is able to introduce negative supercoils. Gyrase is essential in bacteria and apparently absent from eukaryotes and is, consequently, an important target for antibacterial agents (e.g., quinolones and coumarins). We have identified four putative gyrase genes in the model plant Arabidopsis thaliana; one gyrA and three gyrB homologues. DNA gyrase protein A (GyrA) has a dual translational initiation site targeting the mature protein to both chloroplasts and mitochondria, and there are individual targeting sequences for two of the DNA gyrase protein B (GyrB) homologues. N-terminal fusions of the organellar targeting sequences to GFPs support the hypothesis that one enzyme is targeted to the chloroplast and another to the mitochondrion, which correlates with supercoiling activity in isolated organelles. Treatment of seedlings and cultured cells with gyrase-specific drugs leads to growth inhibition. Knockout of A. thaliana gyrA is embryo-lethal whereas knockouts in the gyrB genes lead to seedling-lethal phenotypes or severely stunted growth and development. The A. thaliana genes have been cloned in Escherichia coli and found to complement gyrase temperature-sensitive strains. This report confirms the existence of DNA gyrase in eukaryotes and has important implications for drug targeting, organelle replication, and the evolution of topos in plants. PMID:15136745

  20. Comparative analyses of chloroplast genome data representing nine green algae in Sphaeropleales (Chlorophyceae, Chlorophyta).

    Science.gov (United States)

    Fučíková, Karolina; Lewis, Louise A; Lewis, Paul O

    2016-06-01

    The chloroplast genomes of green algae are highly variable in their architecture. In this article we summarize gene content across newly obtained and published chloroplast genomes in Chlorophyceae, including new data from nine of species in Sphaeropleales (Chlorophyceae, Chlorophyta). We present genome architecture information, including genome synteny analysis across two groups of species. Also, we provide a phylogenetic tree obtained from analysis of gene order data for species in Chlorophyceae with fully sequenced chloroplast genomes. Further analyses and interpretation of the data can be found in "Chloroplast phylogenomic data from the green algal order Sphaeropleales (Chlorophyceae, Chlorophyta) reveal complex patterns of sequence evolution" (Fučíková et al., In review) [1]. PMID:27054159

  1. Running a little late: chloroplast Fe status and the circadian clock

    OpenAIRE

    Wilson, Grandon T; Erin L Connolly

    2013-01-01

    Iron homeostasis is essential for plant growth and survival. Two papers now report that chloroplast Iron levels also regulate the period of the circadian clock, which might confer fitness advantage by linking iron status to daily changes in environmental conditions.

  2. Development of the First Chloroplast Microsatellite Loci in Ginkgo biloba (Ginkgoaceae

    Directory of Open Access Journals (Sweden)

    Chun-Xiang Xie

    2013-07-01

    Full Text Available Premise of the study: To investigate population genetics, phylogeography, and cultivar origin of Ginkgo biloba, chloroplast microsatellite primers were developed. Methods and Results: Twenty-one chloroplast microsatellite markers were identified referring to the two published chloroplast genomes of G. biloba. Polymorphisms were assessed on four natural populations from the two refugia in China. Eight loci were detected to be polymorphic in these populations. The number of alleles per locus ranged from three to seven, and the unbiased haploid diversity per locus varied from 0.441 to 0.807. Conclusions: For the first time, we developed 21 chloroplast microsatellite markers for G. biloba, including 13 monomorphic and eight polymorphic ones within the assessed natural populations. These markers should provide a powerful tool for the study of genetic variation of both natural and cultivated populations of G. biloba, as well as cultivars.

  3. The complete chloroplast genome sequence of an important medicinal plant Cynanchum wilfordii (Maxim.) Hemsl. (Apocynaceae).

    Science.gov (United States)

    Park, Hyun-Seung; Kim, Kyu-Yeob; Kim, Kyunghee; Lee, Sang-Choon; Lee, Junki; Seong, Rack Seon; Shim, Young Hun; Sung, Sang Hyun; Yang, Tae-Jin

    2016-09-01

    Cynanchum wilfordii (Maxim.) Hemsl. is a traditional medicinal herb belonging to the Asclepiadoideae subfamily, whose dried roots have been used as traditional medicine in Asia. The complete chloroplast genome of C. wilfordii was generated by de novo assembly using the small amount of whole genome sequencing data. The chloroplast genome of C. wilfordii was 161 241 bp long, composed of large single copy region (91 995 bp), small single copy region (19 930 bp) and a pair of inverted repeat regions (24 658 bp). The overall GC contents of the chloroplast genome was 37.8%. A total of 114 genes were annotated, which included 80 protein-coding genes, 30 tRNA genes and 4 rRNA genes. Phylogenetic analysis with the reported chloroplast genomes revealed that C. wilfordii is most closely related to Asclepias nivea (Caribbean milkweed) and Asclepias syriaca (common milkweed) within the Asclepiadoideae subfamily. PMID:26358391

  4. The complete chloroplast genome of Eleutherococcus gracilistylus (W.W.Sm.) S.Y.Hu (Araliaceae).

    Science.gov (United States)

    Kim, Kyunghee; Lee, Junki; Lee, Sang-Choon; Kim, Nam-Hoon; Jang, Woojong; Kim, Soonok; Sung, Sangmin; Lee, Jungho; Yang, Tae-Jin

    2016-09-01

    Eleutherococcus gracilistylus is a plant species that is close to E. senticosus, a famous medicinal plant called Siberian ginseng. The complete chloroplast genome sequence of the E. gracilistylus was determined by de novo assembly using whole genome next generation sequences. The chloroplast genome of E. gracilistylus was 156 770 bp long and showed distinct four partite structures such as a large single copy region of 86 729 bp, a small single copy region of 18 175 bp, and a pair of inverted repeat regions of 25 933 bp. The overall GC contents of the genome sequence were 36.8%. The chloroplast genome of E. gracilistylus contains 79 protein-coding sequences, 30 tRNA genes, and four rRNA genes. The phylogenetic analysis with the reported chloroplast genomes confirmed close taxonomical relationship of E. gracilistylus with E. senticosus. PMID:26358682

  5. In Vivo Quantification of Peroxisome Tethering to Chloroplasts in Tobacco Epidermal Cells Using Optical Tweezers.

    Science.gov (United States)

    Gao, Hongbo; Metz, Jeremy; Teanby, Nick A; Ward, Andy D; Botchway, Stanley W; Coles, Benjamin; Pollard, Mark R; Sparkes, Imogen

    2016-01-01

    Peroxisomes are highly motile organelles that display a range of motions within a short time frame. In static snapshots, they can be juxtaposed to chloroplasts, which has led to the hypothesis that they are physically interacting. Here, using optical tweezers, we tested the dynamic physical interaction in vivo. Using near-infrared optical tweezers combined with TIRF microscopy, we were able to trap peroxisomes and approximate the forces involved in chloroplast association in vivo in tobacco (Nicotiana tabacum) and observed weaker tethering to additional unknown structures within the cell. We show that chloroplasts and peroxisomes are physically tethered through peroxules, a poorly described structure in plant cells. We suggest that peroxules have a novel role in maintaining peroxisome-organelle interactions in the dynamic environment. This could be important for fatty acid mobilization and photorespiration through the interaction with oil bodies and chloroplasts, highlighting a fundamentally important role for organelle interactions for essential biochemistry and physiological processes. PMID:26518344

  6. Regulation of chloroplast number and DNA synthesis in higher plants. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Mullet, J.E.

    1995-11-10

    The long term objective of this research is to understand the process of chloroplast development and its coordination with leaf development in higher plants. This is important because the photosynthetic capacity of plants is directly related to leaf and chloroplast development. This research focuses on obtaining a detailing description of leaf development and the early steps in chloroplast development including activation of plastid DNA synthesis, changes in plastid DNA copy number, activation of chloroplast transcription and increases in plastid number per cell. The grant will also begin analysis of specific biochemical mechanisms by isolation of the plastid DNA polymerase, and identification of genetic mutants which are altered in their accumulation of plastid DNA and plastid number per cell.

  7. Regulation of chloroplast number and DNA synthesis in higher plants. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Mullet, J.E.

    1995-11-10

    The long term objective of this research is to understand the process of chloroplast development and its coordination with leaf development in higher plants. This is important because the photosynthetic capacity of plants is directly related to leaf and chloroplast development. This research focuses on obtaining a detailed description of leaf development and the early steps in chloroplast development including activation of plastid DNA synthesis, changes in plastid DNA copy number, activation of chloroplast transcription and increases in plastid number per cell. The grant will also begin analysis of specific biochemical mechanisms by isolation of the plastid DNA polymerase, and identification of genetic mutants which are altered in their accumulation of plastid DNA and plastid number per cell.

  8. Genetic variation and control of chloroplast pigment concentrations in Picea rubens, Picea mariana and their hybrids. I. Ambient and elevated [CO2] environments

    International Nuclear Information System (INIS)

    A significant decline has been noted in the red spruce component of the Acadian forest region in eastern Canada and the northeastern United States as a result of excessive harvesting, acid rain, and global warming. Two experiments were performed to acquire benchmark adaptive traits for information from a red spruce (RS) (Picea rubens Sargand) and black spruce (BS) (P. mariana (Mill.) B.S.P.) genetic complex grown in ambient carbon dioxide concentration ([CO2]). The first experiment involved RS-BS seed sources from across the RS geographical range, while the second experiment involved an intra- and interspecific controlled-cross experiment to determine if RS and BS have unique chloroplast pigment concentrations and traits that reflect adaptations to different ecological niches. The objective was to determine species origin and hybrid variations in chloroplast pigment concentrations; examine the effect of elevated [CO2] on chloroplast pigments; determine the inheritance of chloroplast pigments and examine the relationship of chloroplast pigment concentrations of trees grown at ambient [CO2] with productivity traits and nitrogen concentrations. The traits related to light-energy processing have pronounced ecological implications for plant health. Results from the species origin experiment showed that total chlorophyll concentration was about 15 per cent higher in ambient [CO2] than in elevated [CO2]. In ambient [CO2], BS populations had 11 per cent higher total chlorophyll and carotenoid concentrations than RS populations. Results from the controlled-cross experiment showed that families with a hybrid index of 25 per cent RS had the highest total chlorophyll concentrations, and families with hybrid indices of 75 and 100 had the lowest amounts. A predominant male effect for chlorophyll concentration was noted. In ambient and elevated [CO2] environments, crosses with BS males had 10.6 and 17.6 per cent higher total chlorophyll concentrations than crosses with hybrid and

  9. Sporadic inclusion body myositis in Japanese is associated with the MHC ancestral haplotype 52.1.

    Science.gov (United States)

    Scott, Adrian Phillip; Allcock, Richard James Nigel; Mastaglia, Frank; Nishino, Ichizo; Nonaka, Ikuya; Laing, Nigel

    2006-05-01

    In Caucasians, sporadic inclusion body myositis has been associated with the MHC ancestral haplotypes; HLA-A1, B8, DR3 (8.1AH) and HLA-B35, DR1 (35.2AH). It is not known whether these haplotypes carry susceptibility for the disease in other ethnic groups. We report here the results of HLA-B and -DRB1 typing using a high-resolution sequence-based technique in a cohort of 31 Japanese patients with definite sIBM. Patient allele frequencies were 40.3% for HLA-B*5201 (10.7% in controls: pHLA-DRB1*1502 (10% in controls: p<0.001). Both alleles were found together as part of a conserved haplotype (52.1AH) at a frequency of 37.1% in patients (8.4% in controls: p<0.001). This is the first description of a haplotypic MHC association with sporadic inclusion body myositis in Japanese patients. These findings indicate that different MHC ancestral haplotypes are associated with sIBM in different ethnic groups and further emphasize the importance of genetic factors in this condition. PMID:16564169

  10. Contributions of ancestral inter-species recombination to the genetic diversity of extant Streptomyces lineages.

    Science.gov (United States)

    Andam, Cheryl P; Choudoir, Mallory J; Vinh Nguyen, Anh; Sol Park, Han; Buckley, Daniel H

    2016-07-01

    Streptomyces species produce many important antibiotics and have a crucial role in soil nutrient cycling. However, their evolutionary history remains poorly characterized. We have evaluated the impact of homologous recombination on the evolution of Streptomyces using multi-locus sequence analysis of 234 strains that represent at least 11 species clusters. Evidence of inter-species recombination is widespread but not uniform within the genus and levels of mosaicism vary between species clusters. Most phylogenetically incongruent loci are monophyletic at the scale of species clusters and their subclades, suggesting that these recombination events occurred in shared ancestral lineages. Further investigation of two mosaic species clusters suggests that genes acquired by inter-species recombination may have become fixed in these lineages during periods of demographic expansion; implicating a role for phylogeography in determining contemporary patterns of genetic diversity. Only by examining the phylogeny at the scale of the genus is apparent that widespread phylogenetically incongruent loci in Streptomyces are derived from a far smaller number of ancestral inter-species recombination events. PMID:26849310

  11. Comparative analysis of rosaceous genomes and the reconstruction of a putative ancestral genome for the family

    Directory of Open Access Journals (Sweden)

    Velasco Riccardo

    2011-01-01

    Full Text Available Abstract Background Comparative genome mapping studies in Rosaceae have been conducted until now by aligning genetic maps within the same genus, or closely related genera and using a limited number of common markers. The growing body of genomics resources and sequence data for both Prunus and Fragaria permits detailed comparisons between these genera and the recently released Malus × domestica genome sequence. Results We generated a comparative analysis using 806 molecular markers that are anchored genetically to the Prunus and/or Fragaria reference maps, and physically to the Malus genome sequence. Markers in common for Malus and Prunus, and Malus and Fragaria, respectively were 784 and 148. The correspondence between marker positions was high and conserved syntenic blocks were identified among the three genera in the Rosaceae. We reconstructed a proposed ancestral genome for the Rosaceae. Conclusions A genome containing nine chromosomes is the most likely candidate for the ancestral Rosaceae progenitor. The number of chromosomal translocations observed between the three genera investigated was low. However, the number of inversions identified among Malus and Prunus was much higher than any reported genome comparisons in plants, suggesting that small inversions have played an important role in the evolution of these two genera or of the Rosaceae.

  12. Bearing the unbearable: ancestral transmission through dreams and moving metaphors in the analtyic field.

    Science.gov (United States)

    Pickering, Judith

    2012-11-01

    This paper explores how untold and unresolved intergenerational trauma may be transmitted through unconscious channels of communication, manifesting in the dreams of descendants. Unwitting carriers for that which was too horrific for their ancestors to bear, descendants may enter analysis through an unconscious need to uncover past secrets, piece together ancestral histories before the keys to comprehending their terrible inheritance die with their forebears. They seek the relational containment of the analytic relationship to provide psychological conditions to bear the unbearable, know the unknowable, speak the unspeakable and redeem the unredeemable. In the case of 'Rachael', initial dreams gave rise to what Hobson (1984) called 'moving metaphors of self' in the analytic field. Dream imagery, projective and introjective processes in the transference-countertransference dynamics gradually revealed an unknown ancestral history. I clarify the back and forth process from dream to waking dream thoughts to moving metaphors and differentiate the moving metaphor from a living symbol. I argue that the containment of the analytic relationship nested within the security of the analytic space is a necessary precondition for such healing processes to occur. PMID:23130614

  13. RNA-DNA differences in human mitochondria restore ancestral form of 16S ribosomal RNA.

    Science.gov (United States)

    Bar-Yaacov, Dan; Avital, Gal; Levin, Liron; Richards, Allison L; Hachen, Naomi; Rebolledo Jaramillo, Boris; Nekrutenko, Anton; Zarivach, Raz; Mishmar, Dan

    2013-11-01

    RNA transcripts are generally identical to the underlying DNA sequences. Nevertheless, RNA-DNA differences (RDDs) were found in the nuclear human genome and in plants and animals but not in human mitochondria. Here, by deep sequencing of human mitochondrial DNA (mtDNA) and RNA, we identified three RDD sites at mtDNA positions 295 (C-to-U), 13710 (A-to-U, A-to-G), and 2617 (A-to-U, A-to-G). Position 2617, within the 16S rRNA, harbored the most prevalent RDDs (>30% A-to-U and ∼15% A-to-G of the reads in all tested samples). The 2617 RDDs appeared already at the precursor polycistrone mitochondrial transcript. By using traditional Sanger sequencing, we identified the A-to-U RDD in six different cell lines and representative primates (Gorilla gorilla, Pongo pigmaeus, and Macaca mulatta), suggesting conservation of the mechanism generating such RDD. Phylogenetic analysis of more than 1700 vertebrate mtDNA sequences supported a thymine as the primate ancestral allele at position 2617, suggesting that the 2617 RDD recapitulates the ancestral 16S rRNA. Modeling U or G (the RDDs) at position 2617 stabilized the large ribosomal subunit structure in contrast to destabilization by an A (the pre-RDDs). Hence, these mitochondrial RDDs are likely functional. PMID:23913925

  14. Ancestral origin of the ATTCT repeat expansion in spinocerebellar ataxia type 10 (SCA10.

    Directory of Open Access Journals (Sweden)

    Teresa Almeida

    Full Text Available Spinocerebellar ataxia type 10 (SCA10 is an autosomal dominant neurodegenerative disease characterized by cerebellar ataxia and seizures. The disease is caused by a large ATTCT repeat expansion in the ATXN10 gene. The first families reported with SCA10 were of Mexican origin, but the disease was soon after described in Brazilian families of mixed Portuguese and Amerindian ancestry. The origin of the SCA10 expansion and a possible founder effect that would account for its geographical distribution have been the source of speculation over the last years. To unravel the mutational origin and spread of the SCA10 expansion, we performed an extensive haplotype study, using closely linked STR markers and intragenic SNPs, in families from Brazil and Mexico. Our results showed (1 a shared disease haplotype for all Brazilian and one of the Mexican families, and (2 closely-related haplotypes for the additional SCA10 Mexican families; (3 little or null genetic distance in small normal alleles of different repeat sizes, from the same SNP lineage, indicating that they are being originated by a single step mechanism; and (4 a shared haplotype for pure and interrupted expanded alleles, pointing to a gene conversion model for its generation. In conclusion, we show evidence for an ancestral common origin for SCA10 in Latin America, which might have arisen in an ancestral Amerindian population and later have been spread into the mixed populations of Mexico and Brazil.

  15. In silico resurrection of the major vault protein suggests it is ancestral in modern eukaryotes.

    Science.gov (United States)

    Daly, Toni K; Sutherland-Smith, Andrew J; Penny, David

    2013-01-01

    Vaults are very large oligomeric ribonucleoproteins conserved among a variety of species. The rat vault 3D structure shows an ovoid oligomeric particle, consisting of 78 major vault protein monomers, each of approximately 861 amino acids. Vaults are probably the largest ribonucleoprotein structures in eukaryote cells, being approximately 70 nm in length with a diameter of 40 nm--the size of three ribosomes and with a lumen capacity of 50 million Å(3). We use both protein sequences and inferred ancestral sequences for in silico virtual resurrection of tertiary and quaternary structures to search for vaults in a wide variety of eukaryotes. We find that the vault's phylogenetic distribution is widespread in eukaryotes, but is apparently absent in some notable model organisms. Our conclusion from the distribution of vaults is that they were present in the last eukaryote common ancestor but they have apparently been lost from a number of groups including fungi, insects, and probably plants. Our approach of inferring ancestral 3D and quaternary structures is expected to be useful generally. PMID:23887922

  16. Arabidopsis VARIEGATED 3 encodes a chloroplast-targeted, zinc-finger protein required for chloroplast and palisade cell development

    DEFF Research Database (Denmark)

    Næsted, Henrik; Holm, Agnethe; Jenkins, Tom; Nielsen, Henrik Bjørn; Harris, Cassandra A.; Beale, Michael H.; Andersen, Mathias; Mant, Alexandra; Scheller, Henrik Vibe; Camara, Bilal; Mattsson, Ole; Mundy, John

    2004-01-01

    The stable, recessive Arabidopsis variegated 3 (var3) mutant exhibits a variegated phenotype due to somatic areas lacking or containing developmentally retarded chloroplasts and greatly reduced numbers of palisade cells. The VAR3 gene, isolated by transposon tagging, encodes the 85.9 kDa VAR3 pro...... pigment profiles are qualitatively similar in wild type and var3, although var3 accumulates lower levels of chlorophylls and carotenoids. These results indicate that VAR3 is a part of a protein complex required for normal chloroplast and palisade cell development....... protein containing novel repeats and zinc fingers described as protein interaction domains. VAR3 interacts specifically in yeast and in vitro with NCED4, a putative polyene chain or carotenoid dioxygenase, and both VAR3 and NCED4 accumulate in the chloroplast stroma. Metabolic profiling demonstrates that...

  17. PAPP5 is involved in the tetrapyrrole mediated plastid signalling during chloroplast development

    OpenAIRE

    Juan de Dios Barajas-López; Dmitry Kremnev; Jehad Shaikhali; Aurora Piñas-Fernández; Asa Strand

    2013-01-01

    The initiation of chloroplast development in the light is dependent on nuclear encoded components. The nuclear genes encoding key components in the photosynthetic machinery are regulated by signals originating in the plastids. These plastid signals play an essential role in the regulation of photosynthesis associated nuclear genes (PhANGs) when proplastids develop into chloroplasts. One of the plastid signals is linked to the tetrapyrrole biosynthesis and accumulation of the intermediates the...

  18. Milestones in chloroplast genetic engineering: an environmentally friendly era in biotechnology

    OpenAIRE

    Daniell, Henry; Khan, Muhammad S.; Allison, Lori

    2002-01-01

    Chloroplast genomes defied the laws of Mendelian inheritance at the dawn of plant genetics, and continue to defy the mainstream approach to biotechnology, leading the field in an environmentally friendly direction. Recent success in engineering the chloroplast genome for resistance to herbicides, insects, disease and drought, and for production of biopharmaceuticals, has opened the door to a new era in biotechnology. The successful engineering of tomato chromoplasts for high-level transgene e...

  19. Chloroplast-Derived Vaccine Antigens and Biopharmaceuticals: Expression, Folding, Assembly and Functionality

    OpenAIRE

    Chebolu, S.; Daniell, H

    2009-01-01

    Chloroplast genetic engineering offers several advantages, including high levels of transgene expression, transgene containment via maternal inheritance, and multi-gene expression in a single transformation event. Oral delivery is facilitated by hyperexpression of vaccine antigens against cholera, tetanus, anthrax, plague, or canine parvovirus (4%–31% of total soluble protein, TSP) in transgenic chloroplasts (leaves) or non-green plastids (carrots, tomato) as well as the availability of antib...

  20. Comparative analyses of chloroplast genome data representing nine green algae in Sphaeropleales (Chlorophyceae, Chlorophyta)

    OpenAIRE

    Fučíková, Karolina; Lewis, Louise A.; Lewis, Paul O.

    2016-01-01

    The chloroplast genomes of green algae are highly variable in their architecture. In this article we summarize gene content across newly obtained and published chloroplast genomes in Chlorophyceae, including new data from nine of species in Sphaeropleales (Chlorophyceae, Chlorophyta). We present genome architecture information, including genome synteny analysis across two groups of species. Also, we provide a phylogenetic tree obtained from analysis of gene order data for species in Chlorophy...

  1. Large-scale Arabidopsis phosphoproteome profiling reveals novel chloroplast kinase substrates and phosphorylation networks

    OpenAIRE

    Reiland, S; Messerli, G.; Baerenfaller, K.; Gerrits, B.; Endler, A; Grossmann, J.; Gruissem, W; Baginsky, S

    2009-01-01

    We have characterized the phosphoproteome of Arabidopsis (Arabidopsis thaliana) seedlings using high-accuracy mass spectrometry and report the identification of 1,429 phosphoproteins and 3,029 unique phosphopeptides. Among these, 174 proteins were chloroplast phosphoproteins. Motif-X (motif extractor) analysis of the phosphorylation sites in chloroplast proteins identified four significantly enriched kinase motifs, which include casein kinase II (CKII) and proline-directed kinase motifs, as w...

  2. Increased resistance to oxidative stress in transgenic plants that overexpress chloroplastic Cu/Zn superoxide dismutase.

    OpenAIRE

    Gupta, A. S.; Heinen, J L; Holaday, A S; Burke, J. J.; Allen, R D

    1993-01-01

    Transgenic tobacco plants that express a chimeric gene that encodes chloroplast-localized Cu/Zn superoxide dismutase (SOD) from pea have been developed. To investigate whether increased expression of chloroplast-targeted SOD could alter the resistance of photosynthesis to environmental stress, these plants were subjected to chilling temperatures and moderate (500 mumol of quanta per m2 per s) or high (1500 mumol of quanta per m2 per s) light intensity. During exposure to moderate stress, tran...

  3. Chloroplast envelope membranes: a dynamic interface between plastids and the cytosol

    OpenAIRE

    Block, Maryse A.; Douce, Roland; Joyard, Jacques; Rolland, Norbert

    2007-01-01

    Chloroplasts are bounded by a pair of outer membranes, the envelope, that is the only permanent membrane structure of the different types of plastids. Chloroplasts have had a long and complex evolutionary past and integration of the envelope membranes in cellular functions is the result of this evolution. Plastid envelope membranes contain a wide diversity of lipids and terpenoid compounds serving numerous biochemical functions and the flexibility of their biosynthetic pathways allow plants t...

  4. Stress induces the assembly of RNA granules in the chloroplast of Chlamydomonas reinhardtii

    OpenAIRE

    Uniacke, James; Zerges, William

    2008-01-01

    Eukaryotic cells under stress repress translation and localize these messenger RNAs (mRNAs) to cytoplasmic RNA granules. We show that specific stress stimuli induce the assembly of RNA granules in an organelle with bacterial ancestry, the chloroplast of Chlamydomonas reinhardtii. These chloroplast stress granules (cpSGs) form during oxidative stress and disassemble during recovery from stress. Like mammalian stress granules, cpSGs contain poly(A)-binding protein and the small, but not the lar...

  5. An Improved Protocol for Intact Chloroplasts and cpDNA Isolation in Conifers

    OpenAIRE

    Vieira, Leila do Nascimento; Faoro, Helisson; Fraga, Hugo Pacheco de Freitas; Rogalski, Marcelo; de Souza, Emanuel Maltempi; de Oliveira Pedrosa, Fábio; Nodari, Rubens Onofre; Guerra, Miguel Pedro

    2014-01-01

    Background Performing chloroplast DNA (cpDNA) isolation is considered a major challenge among different plant groups, especially conifers. Isolating chloroplasts in conifers by such conventional methods as sucrose gradient and high salt has not been successful. So far, plastid genome sequencing protocols for conifer species have been based mainly on long-range PCR, which is known to be time-consuming and difficult to implement. Methodology/Principal Findings We developed a protocol for cpDNA ...

  6. The Complete Chloroplast Genome of Banana (Musa acuminata, Zingiberales): Insight into Plastid Monocotyledon Evolution

    OpenAIRE

    Guillaume Martin; Franc-Christophe Baurens; Céline Cardi; Jean-Marc Aury; Angélique D'Hont

    2013-01-01

    BACKGROUND: Banana (genus Musa) is a crop of major economic importance worldwide. It is a monocotyledonous member of the Zingiberales, a sister group of the widely studied Poales. Most cultivated bananas are natural Musa inter-(sub-)specific triploid hybrids. A Musa acuminata reference nuclear genome sequence was recently produced based on sequencing of genomic DNA enriched in nucleus. METHODOLOGY/PRINCIPAL FINDINGS: The Musa acuminata chloroplast genome was assembled with chloroplast reads e...

  7. Sorting signals, N-terminal modifications and abundance of the chloroplast proteome.

    Directory of Open Access Journals (Sweden)

    Boris Zybailov

    Full Text Available Characterization of the chloroplast proteome is needed to understand the essential contribution of the chloroplast to plant growth and development. Here we present a large scale analysis by nanoLC-Q-TOF and nanoLC-LTQ-Orbitrap mass spectrometry (MS of ten independent chloroplast preparations from Arabidopsis thaliana which unambiguously identified 1325 proteins. Novel proteins include various kinases and putative nucleotide binding proteins. Based on repeated and independent MS based protein identifications requiring multiple matched peptide sequences, as well as literature, 916 nuclear-encoded proteins were assigned with high confidence to the plastid, of which 86% had a predicted chloroplast transit peptide (cTP. The protein abundance of soluble stromal proteins was calculated from normalized spectral counts from LTQ-Obitrap analysis and was found to cover four orders of magnitude. Comparison to gel-based quantification demonstrates that 'spectral counting' can provide large scale protein quantification for Arabidopsis. This quantitative information was used to determine possible biases for protein targeting prediction by TargetP and also to understand the significance of protein contaminants. The abundance data for 550 stromal proteins was used to understand abundance of metabolic pathways and chloroplast processes. We highlight the abundance of 48 stromal proteins involved in post-translational proteome homeostasis (including aminopeptidases, proteases, deformylases, chaperones, protein sorting components and discuss the biological implications. N-terminal modifications were identified for a subset of nuclear- and chloroplast-encoded proteins and a novel N-terminal acetylation motif was discovered. Analysis of cTPs and their cleavage sites of Arabidopsis chloroplast proteins, as well as their predicted rice homologues, identified new species-dependent features, which will facilitate improved subcellular localization prediction. No evidence

  8. Uncovering the protein lysine and arginine methylation network in Arabidopsis chloroplasts.

    Science.gov (United States)

    Alban, Claude; Tardif, Marianne; Mininno, Morgane; Brugière, Sabine; Gilgen, Annabelle; Ma, Sheng; Mazzoleni, Meryl; Gigarel, Océane; Martin-Laffon, Jacqueline; Ferro, Myriam; Ravanel, Stéphane

    2014-01-01

    Post-translational modification of proteins by the addition of methyl groups to the side chains of Lys and Arg residues is proposed to play important roles in many cellular processes. In plants, identification of non-histone methylproteins at a cellular or subcellular scale is still missing. To gain insights into the extent of this modification in chloroplasts we used a bioinformatics approach to identify protein methyltransferases targeted to plastids and set up a workflow to specifically identify Lys and Arg methylated proteins from proteomic data used to produce the Arabidopsis chloroplast proteome. With this approach we could identify 31 high-confidence Lys and Arg methylation sites from 23 chloroplastic proteins, of which only two were previously known to be methylated. These methylproteins are split between the stroma, thylakoids and envelope sub-compartments. They belong to essential metabolic processes, including photosynthesis, and to the chloroplast biogenesis and maintenance machinery (translation, protein import, division). Also, the in silico identification of nine protein methyltransferases that are known or predicted to be targeted to plastids provided a foundation to build the enzymes/substrates relationships that govern methylation in chloroplasts. Thereby, using in vitro methylation assays with chloroplast stroma as a source of methyltransferases we confirmed the methylation sites of two targets, plastid ribosomal protein L11 and the β-subunit of ATP synthase. Furthermore, a biochemical screening of recombinant chloroplastic protein Lys methyltransferases allowed us to identify the enzymes involved in the modification of these substrates. The present study provides a useful resource to build the methyltransferases/methylproteins network and to elucidate the role of protein methylation in chloroplast biology. PMID:24748391

  9. THE OCCURRENCE AND SIGNIFICANCE OF ENDOSYMBIOTIC CHLOROPLASTS IN THE DIGESTIVE GLANDS OF HERBIVOROUS OPISTHOBRANCHS(1).

    Science.gov (United States)

    Taylor, D L

    1967-12-01

    Intact algal chloroplasts have been found in the digestive glands of 5 species of Opisthobranchia belonging to the order Saccoglossa. Preliminary studies on 3 of these confirm their endosymbiotic nature. It is suggested that the occurrence of these endosymbiotic organelles may be widespread among related species of Saccoglossa. Their independent functional existence supports the view that chloroplasts possess a system of nonchromosomal inheritance. PMID:27065036

  10. Complete Chloroplast Genome Sequence of Omani Lime (Citrus aurantiifolia) and Comparative Analysis within the Rosids

    OpenAIRE

    Huei-Jiun Su; Hogenhout, Saskia A.; Al-Sadi, Abdullah M.; Chih-Horng Kuo

    2014-01-01

    The genus Citrus contains many economically important fruits that are grown worldwide for their high nutritional and medicinal value. Due to frequent hybridizations among species and cultivars, the exact number of natural species and the taxonomic relationships within this genus are unclear. To compare the differences between the Citrus chloroplast genomes and to develop useful genetic markers, we used a reference-assisted approach to assemble the complete chloroplast genome of Omani lime (C....

  11. Comparative proteomics of chloroplasts envelopes from bundle sheath and mesophyll chloroplasts reveals novel membrane proteins with a possible role in C4-related metabolite fluxes and development.

    Directory of Open Access Journals (Sweden)

    Kalpana eManandhar-Shrestha

    2013-03-01

    Full Text Available As the world population grows, our need for food increases drastically. Limited amounts of arable land lead to a competition between food and fuel crops, while changes in the global climate may impact future crop yields. Thus, a second green revolution will need a better understanding of the processes essential for plant growth and development. One approach toward the solution of this problem is to better understand regulatory and transport processes in C4 plants. C4 plants display an up to 10-fold higher apparent CO2 assimilation and higher yields while maintaining high water use efficiency. This requires differential regulation of mesophyll (M and bundle sheath (BS chloroplast development as well as higher metabolic fluxes of photosynthetic intermediates between cells and across chloroplast envelopes. While previous analyses of overall chloroplast membranes have yielded significant insight, our comparative proteomics approach using enriched BS and M chloroplast envelopes of Zea mays allowed us to identify 37 proteins of unknown function that have not been seen in these earlier studies. We identified 280 proteins, 84% of which are known/predicted to be present in chloroplasts (cp. 74% have a known or predicted membrane association. 21 membrane proteins were 2-15 times more abundant in BS cells, while 36 proteins were more abundant in M cp envelopes. These proteins could represent additional candidates of proteins essential for development or metabolite transport processes in C4 plants. RT-PCR confirmed differential expression of thirteen candidate genes. Cp association was confirmed using GFP labeling. Genes for a PIC-like protein and an ER-AP-like protein show an early transient increase in gene expression during the transition to light. In addition, PIC gene expression is increased in the immature part of the leaf and was lower in the fully developed parts of the leaf, suggesting a need for/incorporation of the protein during chloroplast

  12. Identification of the ancestral haplotype for apolipoprotein B suggests an African origin of Homo sapiens sapiens and traces their subsequent migration to Europe and the Pacific.

    OpenAIRE

    Rapacz, J; Chen, L.; Butler-Brunner, E; Wu, M J; Hasler-Rapacz, J O; Butler, R.; Schumaker, V N

    1991-01-01

    The probable ancestral haplotype for human apolipoprotein B (apoB) has been identified through immunological analysis of chimpanzee and gorilla serum and sequence analysis of their DNA. Moreover, the frequency of this ancestral apoB haplotype among different human populations provides strong support for the African origin of Homo sapiens sapiens and their subsequent migration from Africa to Europe and to the Pacific. The approach used here for the identification of the ancestral human apoB ha...

  13. Ancestral state reconstruction of body size in the Caniformia (Carnivora, Mammalia): the effects of incorporating data from the fossil record.

    Science.gov (United States)

    Finarelli, John A; Flynn, John J

    2006-04-01

    A recent molecular phylogeny of the mammalian order Carnivora implied large body size as the ancestral condition for the caniform subclade Arctoidea using the distribution of species mean body sizes among living taxa. "Extant taxa-only" approaches such as these discount character state observations for fossil members of living clades and completely ignore data from extinct lineages. To more rigorously reconstruct body sizes of ancestral forms within the Caniformia, body size and first appearance data were collected for 149 extant and 367 extinct taxa. Body sizes were reconstructed for four ancestral nodes using weighted squared-change parsimony on log-transformed body mass data. Reconstructions based on extant taxa alone favored large body sizes (on the order of 10 to 50 kg) for the last common ancestors of both the Caniformia and Arctoidea. In contrast, reconstructions incorporating fossil data support small body sizes (fossil data was discarded, body size reconstructions became ambiguous, demonstrating that incorporating both character state and temporal information from fossil taxa unambiguously supports a small ancestral body size, thereby falsifying hypotheses derived from extant taxa alone. Body size reconstructions for Caniformia, Arctoidea, and Musteloidea were not sensitive to potential errors introduced by uncertainty in the position of extinct lineages relative to the molecular topology, or to missing body size data for extinct members of an entire major clade (the aquatic Pinnipedia). Incorporating character state observations and temporal information from the fossil record into hypothesis testing has a significant impact on the ability to reconstruct ancestral characters and constrains the range of potential hypotheses of character evolution. Fossil data here provide the evidence to reliably document trends of both increasing and decreasing body size in several caniform clades. More generally, including fossils in such analyses incorporates evidence of

  14. Different fates of the chloroplast tufA gene following its transfer to the nucleus in green algae.

    OpenAIRE

    Baldauf, S L; Manhart, J R; J.D. Palmer

    1990-01-01

    Previous work suggested that the tufA gene, encoding protein synthesis elongation factor Tu, was transferred from the chloroplast to the nucleus within the green algal lineage giving rise to land plants. In this report we investigate the timing and mode of transfer by examining chloroplast and nuclear DNA from the three major classes of green algae, with emphasis on the class Charophyceae, the proposed sister group to land plants. Filter hybridizations reveal a chloroplast tufA gene in all Ul...

  15. ReAS: Recovery of ancestral sequences for transposable elements from the unassembled reads of a whole genome shotgun.

    Directory of Open Access Journals (Sweden)

    Ruiqiang Li

    2005-09-01

    Full Text Available We describe an algorithm, ReAS, to recover ancestral sequences for transposable elements (TEs from the unassembled reads of a whole genome shotgun. The main assumptions are that these TEs must exist at high copy numbers across the genome and must not be so old that they are no longer recognizable in comparison to their ancestral sequences. Tested on the japonica rice genome, ReAS was able to reconstruct all of the high copy sequences in the Repbase repository of known TEs, and increase the effectiveness of RepeatMasker in identifying TEs from genome sequences.

  16. Genetic interactions reveal that specific defects of chloroplast translation are associated with the suppression of var2-mediated leaf variegation.

    Science.gov (United States)

    Liu, Xiayan; Zheng, Mengdi; Wang, Rui; Wang, Ruijuan; An, Lijun; Rodermel, Steve R; Yu, Fei

    2013-10-01

    Arabidopsis thaliana L. yellow variegated (var2) mutant is defective in a chloroplast FtsH family metalloprotease, AtFtsH2/VAR2, and displays an intriguing green and white leaf variegation. This unique var2-mediated leaf variegation offers a simple yet powerful tool for dissecting the genetic regulation of chloroplast development. Here, we report the isolation and characterization of a new var2 suppressor gene, SUPPRESSOR OF VARIEGATION8 (SVR8), which encodes a putative chloroplast ribosomal large subunit protein, L24. Mutations in SVR8 suppress var2 leaf variegation at ambient temperature and partially suppress the cold-induced chlorosis phenotype of var2. Loss of SVR8 causes unique chloroplast rRNA processing defects, particularly the 23S-4.5S dicistronic precursor. The recovery of the major abnormal processing site in svr8 23S-4.5S precursor indicate that it does not lie in the same position where SVR8/L24 binds on the ribosome. Surprisingly, we found that the loss of a chloroplast ribosomal small subunit protein, S21, results in aberrant chloroplast rRNA processing but not suppression of var2 variegation. These findings suggest that the disruption of specific aspects of chloroplast translation, rather than a general impairment in chloroplast translation, suppress var2 variegation and the existence of complex genetic interactions in chloroplast development. PMID:23721655

  17. RNA transcription in isolated chloroplasts during senescence and rejuvenation of intact cotyledons of CUCURBITA PEPO L. (ZUCCHINI)

    International Nuclear Information System (INIS)

    RNA transcription was studied in intact chloroplasts isolated from cotyledons of Cucurbita pepoL. (zucchini) during their growth and development including natural senescence and rejuvenation. Rejuvenation of cotyledons was studied after decapitation of the epicotyl above the senescing yellow cotyledons. Maximal incorporation of [32P] UTP into overall chloroplast RNA was measured two days after exposure of seedlings to light (day 6 th after the onset of germination), followed by a gradual decrease reaching minimal values at the age of 25-28 days when cotyledons began to yellow and eventually die. Rejuvenation of cotyledons completely restored chloroplast RNA synthesis and fifteen days after decapitation (at the age of 40 days), the values of chloroplast transcription even exceeded that of the maximal transcriptional activity in young cotyledons. Inhibitory analysis with tagetitoxin (a specific inhibitor of plastid encoded chloroplast RNA polymerase (PEP)) showed that in young and rejuvenated cotyledons about 85% of chloroplast RNA polymerase activity was due to PEP and only 15% corresponded to the nuclear encoded plastid RNA polymerase (NEP). Definite regions of two chloroplast encoded genes were amplified by means of PCR technique using specific DNA primers for Rubisco large subunit gene (rbcL) and the housekeeping gene for chloroplast 16S rRNA as well as chloroplast DNA as a template. The appropriate lengths of the amplified DNA fragments were checked by restriction analysis

  18. The novel protein DELAYED PALE-GREENING1 is required for early chloroplast biogenesis in Arabidopsis thaliana.

    Science.gov (United States)

    Liu, Dong; Li, Weichun; Cheng, Jianfeng

    2016-01-01

    Chloroplast biogenesis is one of the most important subjects in plant biology. In this study, an Arabidopsis early chloroplast biogenesis mutant with a delayed pale-greening phenotype (dpg1) was isolated from a T-DNA insertion mutant collection. Both cotyledons and true leaves of dpg1 mutants were initially albino but gradually became pale green as the plant matured. Transmission electron microscopic observations revealed that the mutant displayed a delayed proplastid-to-chloroplast transition. Sequence and transcription analyses showed that AtDPG1 encodes a putatively chloroplast-localized protein containing three predicted transmembrane helices and that its expression depends on both light and developmental status. GUS staining for AtDPG1::GUS transgenic lines showed that this gene was widely expressed throughout the plant and that higher expression levels were predominantly found in green tissues during the early stages of Arabidopsis seedling development. Furthermore, quantitative real-time RT-PCR analyses revealed that a number of chloroplast- and nuclear-encoded genes involved in chlorophyll biosynthesis, photosynthesis and chloroplast development were substantially down-regulated in the dpg1 mutant. These data indicate that AtDPG1 plays an essential role in early chloroplast biogenesis, and its absence triggers chloroplast-to-nucleus retrograde signalling, which ultimately down-regulates the expression of nuclear genes encoding chloroplast-localized proteins. PMID:27160321

  19. Genetic Interactions Reveal that Specific Defects of Chloroplast Translation are Associated with the Suppression of var2-Mediated Leaf Variegation

    Institute of Scientific and Technical Information of China (English)

    Xiayan Liu; Mengdi Zheng; Rui Wang; Ruijuan Wang; Lijun An; Steve R. Rodermel; Fei Yu

    2013-01-01

    Arabidopsis thaliana L. yellow variegated (var2) mutant is defective in a chloroplast FtsH family metalloprotease, AtFtsH2/VAR2, and displays an intriguing green and white leaf variegation. This unique var2-mediated leaf variegation offers a simple yet powerful tool for dissecting the genetic regulation of chloroplast development. Here, we report the isolation and characterization of a new var2 suppressor gene, SUPPRESSOR OF VARIEGATION8 (SVR8), which encodes a putative chloroplast ribosomal large subunit protein, L24. Mutations in SVR8 suppress var2 leaf variegation at ambient temperature and partially suppress the cold-induced chlorosis phenotype of var2. Loss of SVR8 causes unique chloroplast rRNA processing defects, particularly the 23S-4.5S dicistronic precursor. The recovery of the major abnormal processing site in svr8 23S-4.5S precursor indicate that it does not lie in the same position where SVR8/L24 binds on the ribosome. Surprisingly, we found that the loss of a chloroplast ribosomal small subunit protein, S21, results in aberrant chloroplast rRNA processing but not suppression of var2 variegation. These findings suggest that the disruption of specific aspects of chloroplast translation, rather than a general impairment in chloroplast translation, suppress var2 variegation and the existence of complex genetic interactions in chloroplast development.

  20. The imperfect ancestral recombination graph reconstruction problem: upper bounds for recombination and homoplasy.

    Science.gov (United States)

    Lam, Fumei; Tarpine, Ryan; Istrail, Sorin

    2010-06-01

    One of the central problems in computational biology is the reconstruction of evolutionary histories. While models incorporating recombination and homoplasy have been studied separately, a missing component in the theory is a robust and flexible unifying model which incorporates both of these major biological events shaping genetic diversity. In this article, we introduce the first such unifying model and develop algorithms to find the optimal ancestral recombination graph incorporating recombinations and homoplasy events. The power of our framework is the connection between our formulation and the Directed Steiner Arborescence Problem in combinatorial optimization. We implement linear programming techniques as well as heuristics for the Directed Steiner Arborescence Problem, and use our methods to construct evolutionary histories for both simulated and real data sets. PMID:20583925

  1. Where did the chili get its spice? Biogeography of capsaicinoid production in ancestral wild chili species.

    Science.gov (United States)

    Tewksbury, Joshua J; Manchego, Carlos; Haak, David C; Levey, Douglas J

    2006-03-01

    The biogeography of pungency in three species of wild chili in the chaco and surrounding highland habitats of southeastern Bolivia is described. We report that Capsicum chacoense, C. baccatum, and C. eximium are polymorphic for production of capsaicin and its analogs, such that completely pungent and completely nonpungent individuals co-occur in some populations. In C. chacoense, the density of plants and the proportion of pungent plants increased with elevation. Above 900 m, all individuals in all populations except two were pungent; nonpungent individuals in at least one of the two polymorphic populations were likely a result of spreading by humans. The occurrence of pungent and nonpungent individuals in three species of ancestral Capsicum and the geographic variation of pungency within species suggest that production of capsaicin and its analogs entails both costs and benefits, which shift from one locality to another. Determining the selection pressures behind such shifts is necessary to understand the evolution of pungency in chilies. PMID:16572297

  2. Magmatism and Epithermal Gold-Silver Deposits of the Southern Ancestral Cascade Arc, Western Nevada and Eastern California

    Science.gov (United States)

    John, David A.; du Bray, Edward A.; Henry, Christopher D., (compiler); Vikre, Peter

    2015-01-01

    Many epithermal gold-silver deposits are temporally and spatially associated with late Oligocene to Pliocene magmatism of the southern ancestral Cascade arc in western Nevada and eastern California. These deposits, which include both quartz-adularia (low- and intermediate-sulfidation; Comstock Lode, Tonopah, Bodie) and quartz-alunite (high-sulfidation; Goldfield, Paradise Peak) types, were major producers of gold and silver. Ancestral Cascade arc magmatism preceded that of the modern High Cascades arc and reflects subduction of the Farallon plate beneath North America. Ancestral arc magmatism began about 45 Ma, continued until about 3 Ma, and extended from near the Canada-United States border in Washington southward to about 250 km southeast of Reno, Nevada. The ancestral arc was split into northern and southern segments across an inferred tear in the subducting slab between Mount Shasta and Lassen Peak in northern California. The southern segment extends between 42°N in northern California and 37°N in western Nevada and was active from about 30 to 3 Ma. It is bounded on the east by the northeast edge of the Walker Lane. Ancestral arc volcanism represents an abrupt change in composition and style of magmatism relative to that in central Nevada. Large volume, caldera-forming, silicic ignimbrites associated with the 37 to 19 Ma ignimbrite flareup are dominant in central Nevada, whereas volcanic centers of the ancestral arc in western Nevada consist of andesitic stratovolcanoes and dacitic to rhyolitic lava domes that mostly formed between 25 and 4 Ma. Both ancestral arc and ignimbrite flareup magmatism resulted from rollback of the shallowly dipping slab that began about 45 Ma in northeast Nevada and migrated south-southwest with time. Most southern segment ancestral arc rocks have oxidized, high potassium, calc-alkaline compositions with silica contents ranging continuously from about 55 to 77 wt%. Most lavas are porphyritic and contain coarse plagioclase

  3. Evolutionary history of assassin bugs (insecta: hemiptera: Reduviidae: insights from divergence dating and ancestral state reconstruction.

    Directory of Open Access Journals (Sweden)

    Wei Song Hwang

    Full Text Available Assassin bugs are one of the most successful clades of predatory animals based on their species numbers (∼6,800 spp. and wide distribution in terrestrial ecosystems. Various novel prey capture strategies and remarkable prey specializations contribute to their appeal as a model to study evolutionary pathways involved in predation. Here, we reconstruct the most comprehensive reduviid phylogeny (178 taxa, 18 subfamilies to date based on molecular data (5 markers. This phylogeny tests current hypotheses on reduviid relationships emphasizing the polyphyletic Reduviinae and the blood-feeding, disease-vectoring Triatominae, and allows us, for the first time in assassin bugs, to reconstruct ancestral states of prey associations and microhabitats. Using a fossil-calibrated molecular tree, we estimated divergence times for key events in the evolutionary history of Reduviidae. Our results indicate that the polyphyletic Reduviinae fall into 11-14 separate clades. Triatominae are paraphyletic with respect to the reduviine genus Opisthacidius in the maximum likelihood analyses; this result is in contrast to prior hypotheses that found Triatominae to be monophyletic or polyphyletic and may be due to the more comprehensive taxon and character sampling in this study. The evolution of blood-feeding may thus have occurred once or twice independently among predatory assassin bugs. All prey specialists evolved from generalist ancestors, with multiple evolutionary origins of termite and ant specializations. A bark-associated life style on tree trunks is ancestral for most of the lineages of Higher Reduviidae; living on foliage has evolved at least six times independently. Reduviidae originated in the Middle Jurassic (178 Ma, but significant lineage diversification only began in the Late Cretaceous (97 Ma. The integration of molecular phylogenetics with fossil and life history data as presented in this paper provides insights into the evolutionary history of

  4. Characterisation of monotreme caseins reveals lineage-specific expansion of an ancestral casein locus in mammals.

    Science.gov (United States)

    Lefèvre, Christophe M; Sharp, Julie A; Nicholas, Kevin R

    2009-01-01

    Using a milk-cell cDNA sequencing approach we characterised milk-protein sequences from two monotreme species, platypus (Ornithorhynchus anatinus) and echidna (Tachyglossus aculeatus) and found a full set of caseins and casein variants. The genomic organisation of the platypus casein locus is compared with other mammalian genomes, including the marsupial opossum and several eutherians. Physical linkage of casein genes has been seen in the casein loci of all mammalian genomes examined and we confirm that this is also observed in platypus. However, we show that a recent duplication of beta-casein occurred in the monotreme lineage, as opposed to more ancient duplications of alpha-casein in the eutherian lineage, while marsupials possess only single copies of alpha- and beta-caseins. Despite this variability, the close proximity of the main alpha- and beta-casein genes in an inverted tail-tail orientation and the relative orientation of the more distant kappa-casein genes are similar in all mammalian genome sequences so far available. Overall, the conservation of the genomic organisation of the caseins indicates the early, pre-monotreme development of the fundamental role of caseins during lactation. In contrast, the lineage-specific gene duplications that have occurred within the casein locus of monotremes and eutherians but not marsupials, which may have lost part of the ancestral casein locus, emphasises the independent selection on milk provision strategies to the young, most likely linked to different developmental strategies. The monotremes therefore provide insight into the ancestral drivers for lactation and how these have adapted in different lineages. PMID:19874726

  5. Genes Suggest Ancestral Colour Polymorphisms Are Shared across Morphologically Cryptic Species in Arctic Bumblebees.

    Directory of Open Access Journals (Sweden)

    Paul H Williams

    Full Text Available Our grasp of biodiversity is fine-tuned through the process of revisionary taxonomy. If species do exist in nature and can be discovered with available techniques, then we expect these revisions to converge on broadly shared interpretations of species. But for the primarily arctic bumblebees of the subgenus Alpinobombus of the genus Bombus, revisions by some of the most experienced specialists are unusual for bumblebees in that they have all reached different conclusions on the number of species present. Recent revisions based on skeletal morphology have concluded that there are from four to six species, while variation in colour pattern of the hair raised questions as to whether at least seven species might be present. Even more species are supported if we accept the recent move away from viewing species as morphotypes to viewing them instead as evolutionarily independent lineages (EILs using data from genes. EILs are recognised here in practice from the gene coalescents that provide direct evidence for their evolutionary independence. We show from fitting both general mixed Yule/coalescent (GMYC models and Poisson-tree-process (PTP models to data for the mitochondrial COI gene that there is support for nine species in the subgenus Alpinobombus. Examination of the more slowly evolving nuclear PEPCK gene shows further support for a previously unrecognised taxon as a new species in northwestern North America. The three pairs of the most morphologically similar sister species are separated allopatrically and prevented from interbreeding by oceans. We also find that most of the species show multiple shared colour patterns, giving the appearance of mimicry among parts of the different species. However, reconstructing ancestral colour-pattern states shows that speciation is likely to have cut across widespread ancestral polymorphisms, without or largely without convergence. In the particular case of Alpinobombus, morphological, colour-pattern, and

  6. Insights from the complete chloroplast genome into the evolution of Sesamum indicum L.

    Directory of Open Access Journals (Sweden)

    Haiyang Zhang

    Full Text Available Sesame (Sesamum indicum L. is one of the oldest oilseed crops. In order to investigate the evolutionary characters according to the Sesame Genome Project, apart from sequencing its nuclear genome, we sequenced the complete chloroplast genome of S. indicum cv. Yuzhi 11 (white seeded using Illumina and 454 sequencing. Comparisons of chloroplast genomes between S. indicum and the 18 other higher plants were then analyzed. The chloroplast genome of cv. Yuzhi 11 contains 153,338 bp and a total of 114 unique genes (KC569603. The number of chloroplast genes in sesame is the same as that in Nicotiana tabacum, Vitis vinifera and Platanus occidentalis. The variation in the length of the large single-copy (LSC regions and inverted repeats (IR in sesame compared to 18 other higher plant species was the main contributor to size variation in the cp genome in these species. The 77 functional chloroplast genes, except for ycf1 and ycf2, were highly conserved. The deletion of the cp ycf1 gene sequence in cp genomes may be due either to its transfer to the nuclear genome, as has occurred in sesame, or direct deletion, as has occurred in Panax ginseng and Cucumis sativus. The sesame ycf2 gene is only 5,721 bp in length and has lost about 1,179 bp. Nucleotides 1-585 of ycf2 when queried in BLAST had hits in the sesame draft genome. Five repeats (R10, R12, R13, R14 and R17 were unique to the sesame chloroplast genome. We also found that IR contraction/expansion in the cp genome alters its rate of evolution. Chloroplast genes and repeats display the signature of convergent evolution in sesame and other species. These findings provide a foundation for further investigation of cp genome evolution in Sesamum and other higher plants.

  7. Complete chloroplast genome sequences of Mongolia medicine Artemisia frigida and phylogenetic relationships with other plants.

    Directory of Open Access Journals (Sweden)

    Yue Liu

    Full Text Available BACKGROUND: Artemisia frigida Willd. is an important Mongolian traditional medicinal plant with pharmacological functions of stanch and detumescence. However, there is little sequence and genomic information available for Artemisia frigida, which makes phylogenetic identification, evolutionary studies, and genetic improvement of its value very difficult. We report the complete chloroplast genome sequence of Artemisia frigida based on 454 pyrosequencing. METHODOLOGY/PRINCIPAL FINDINGS: The complete chloroplast genome of Artemisia frigida is 151,076 bp including a large single copy (LSC region of 82,740 bp, a small single copy (SSC region of 18,394 bp and a pair of inverted repeats (IRs of 24,971 bp. The genome contains 114 unique genes and 18 duplicated genes. The chloroplast genome of Artemisia frigida contains a small 3.4 kb inversion within a large 23 kb inversion in the LSC region, a unique feature in Asteraceae. The gene order in the SSC region of Artemisia frigida is inverted compared with the other 6 Asteraceae species with the chloroplast genomes sequenced. This inversion is likely caused by an intramolecular recombination event only occurred in Artemisia frigida. The existence of rich SSR loci in the Artemisia frigida chloroplast genome provides a rare opportunity to study population genetics of this Mongolian medicinal plant. Phylogenetic analysis demonstrates a sister relationship between Artemisia frigida and four other species in Asteraceae, including Ageratina adenophora, Helianthus annuus, Guizotia abyssinica and Lactuca sativa, based on 61 protein-coding sequences. Furthermore, Artemisia frigida was placed in the tribe Anthemideae in the subfamily Asteroideae (Asteraceae based on ndhF and trnL-F sequence comparisons. CONCLUSION: The chloroplast genome sequence of Artemisia frigida was assembled and analyzed in this study, representing the first plastid genome sequenced in the Anthemideae tribe. This complete chloroplast genome

  8. Preferential translation of chloroplast ribosomal proteins in Chlamydomonas reinhardtti

    International Nuclear Information System (INIS)

    The nuclear cr-1 mutant of C. reinhardtii is deficient in the 30S subunit of the chloroplast (cp) ribosome and in cp protein synthesis. The cp spectinomycin resistant mutant, spr-u-1-27-3, has a normal level of 70S ribosomes but only a low rate of cp protein synthesis with spectinomycin present. In both mutants there is little accumulation of the large subunit of ribulose 1,5-bisphosphate carboxylase (Rubisco LSU), but near wild-type levels of cp synthesized r-proteins. In cells pulse-labelled with 35SO4 and immunoprecipitated with specific antisera, the ratio of the rate of synthesis of cp r-proteins to that of Rubisco LSU is 7 times greater in both mutants than in wild-type. No difference in the rate of turnover between r-proteins and Rubisco LSU in mutant and wild-type cells was observed during a one hour chase. The mRNA levels for r-protein L1 and Rubisco LSU actually increase slightly in the mutants. These data suggest that C. reinhardtii has a translation mechanism for preferential synthesis of cp r-proteins that operates under conditions of reduced total cp protein synthesis

  9. Identification of the Elusive Pyruvate Reductase of Chlamydomonas reinhardtii Chloroplasts.

    Science.gov (United States)

    Burgess, Steven J; Taha, Hussein; Yeoman, Justin A; Iamshanova, Oksana; Chan, Kher Xing; Boehm, Marko; Behrends, Volker; Bundy, Jacob G; Bialek, Wojciech; Murray, James W; Nixon, Peter J

    2016-01-01

    Under anoxic conditions the green alga Chlamydomonas reinhardtii activates various fermentation pathways leading to the creation of formate, acetate, ethanol and small amounts of other metabolites including d-lactate and hydrogen. Progress has been made in identifying the enzymes involved in these pathways and their subcellular locations; however, the identity of the enzyme involved in reducing pyruvate to d-lactate has remained unclear. Based on sequence comparisons, enzyme activity measurements, X-ray crystallography, biochemical fractionation and analysis of knock-down mutants, we conclude that pyruvate reduction in the chloroplast is catalyzed by a tetrameric NAD(+)-dependent d-lactate dehydrogenase encoded by Cre07.g324550. Its expression during aerobic growth supports a possible function as a 'lactate valve' for the export of lactate to the mitochondrion for oxidation by cytochrome-dependent d-lactate dehydrogenases and by glycolate dehydrogenase. We also present a revised spatial model of fermentation based on our immunochemical detection of the likely pyruvate decarboxylase, PDC3, in the cytoplasm. PMID:26574578

  10. Wood identification with PCR targeting noncoding chloroplast DNA.

    Science.gov (United States)

    Tang, Xiaoshu; Zhao, Guangjie; Ping, Liyan

    2011-12-01

    Wood identification is extremely important in the modern forest industry. It also has significant applications in forensics, as well as in archeology and ecological research. In this study, five universal primer pairs amplifying chloroplast noncoding sequences of 300-1,200 bp were designed. Sequencing these amplicons in combination can lead to reliable identification of logs and wood products to cultivar, ecotype, or even the falling population. These primer pairs work on both gymnosperms and angiosperm trees. They also are potentially applicable to accurately identify shrubs and herbaceous species. In addition, a wood DNA purification method is proposed in which N-phenacylthiazolium bromide (PTB) is used to increase the quality and quantity of extracted DNA. This method was first validated using air-dried timber disks from three different tree species that were felled 4 years ago. The sapwood and outer heartwood provided the best locations for DNA extraction. The method was also successfully applied to extract DNA from the recalcitrant processed white oak wood, randomly selected staves of wine barrels. The single nucleotide polymorphism detected on the oak DNA sequences showed correlation to their geographical origins. PMID:22038094

  11. Artemisinin inhibits chloroplast electron transport activity: mode of action.

    Directory of Open Access Journals (Sweden)

    Adyasha Bharati

    Full Text Available Artemisinin, a secondary metabolite produced in Artemisia plant species, besides having antimalarial properties is also phytotoxic. Although, the phytotoxic activity of the compound has been long recognized, no information is available on the mechanism of action of the compound on photosynthetic activity of the plant. In this report, we have evaluated the effect of artemisinin on photoelectron transport activity of chloroplast thylakoid membrane. The inhibitory effect of the compound, under in vitro condition, was pronounced in loosely and fully coupled thylakoids; being strong in the former. The extent of inhibition was drastically reduced in the presence of uncouplers like ammonium chloride or gramicidin; a characteristic feature described for energy transfer inhibitors. The compound, on the other hand, when applied to plants (in vivo, behaved as a potent inhibitor of photosynthetic electron transport. The major site of its action was identified to be the Q(B; the secondary quinone moiety of photosystemII complex. Analysis of photoreduction kinetics of para-benzoquinone and duroquinone suggest that the inhibition leads to formation of low pool of plastoquinol, which becomes limiting for electron flow through photosystemI. Further it was ascertained that the in vivo inhibitory effect appeared as a consequence of the formation of an unidentified artemisinin-metabolite rather than by the interaction of the compound per se. The putative metabolite of artemisinin is highly reactive in instituting the inhibition of photosynthetic electron flow eventually reducing the plant growth.

  12. Two complete chloroplast genome sequences of Cannabis sativa varieties.

    Science.gov (United States)

    Oh, Hyehyun; Seo, Boyoung; Lee, Seunghwan; Ahn, Dong-Ha; Jo, Euna; Park, Jin-Kyoung; Min, Gi-Sik

    2016-07-01

    In this study, we determined the complete chloroplast (cp) genomes from two varieties of Cannabis sativa. The genome sizes were 153,848 bp (the Korean non-drug variety, Cheungsam) and 153,854 bp (the African variety, Yoruba Nigeria). The genome structures were identical with 131 individual genes [86 protein-coding genes (PCGs), eight rRNA, and 37 tRNA genes]. Further, except for the presence of an intron in the rps3 genes of two C. sativa varieties, the cp genomes of C. sativa had conservative features similar to that of all known species in the order Rosales. To verify the position of C. sativa within the order Rosales, we conducted phylogenetic analysis by using concatenated sequences of all PCGs from 17 complete cp genomes. The resulting tree strongly supported monophyly of Rosales. Further, the family Cannabaceae, represented by C. sativa, showed close relationship with the family Moraceae. The phylogenetic relationship outlined in our study is well congruent with those previously shown for the order Rosales. PMID:26104156

  13. The complete chloroplast genome sequence of Abies nephrolepis (Pinaceae: Abietoideae

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    Dong-Keun Yi

    2016-06-01

    Full Text Available The plant chloroplast (cp genome has maintained a relatively conserved structure and gene content throughout evolution. Cp genome sequences have been used widely for resolving evolutionary and phylogenetic issues at various taxonomic levels of plants. Here, we report the complete cp genome of Abies nephrolepis. The A. nephrolepis cp genome is 121,336 base pairs (bp in length including a pair of short inverted repeat regions (IRa and IRb of 139 bp each separated by a small single copy (SSC region of 54,323 bp (SSC and a large single copy region of 66,735 bp (LSC. It contains 114 genes, 68 of which are protein coding genes, 35 tRNA and four rRNA genes, six open reading frames, and one pseudogene. Seventeen repeat units and 64 simple sequence repeats (SSR have been detected in A. nephrolepis cp genome. Large IR sequences locate in 42-kb inversion points (1186 bp. The A. nephrolepis cp genome is identical to Abies koreana’s which is closely related to taxa. Pairwise comparison between two cp genomes revealed 140 polymorphic sites in each. Complete cp genome sequence of A. nephrolepis has a significant potential to provide information on the evolutionary pattern of Abietoideae and valuable data for development of DNA markers for easy identification and classification.

  14. Antiquity of Ediacaran Fossils, Early Shelled Organisms, Recent Radiometric Age-Dates from India and Ancestral Biota

    Science.gov (United States)

    Basu, A.

    2008-03-01

    U-Pb zircon ages and Pb-Pb limestone ages assign Ediacaran and shelly fossils reported from India between 1750 and 950 Ma indicating ancestral diversification of metazoans. Simple bacterial life must have began earlier and may be found in meteorites.

  15. ReAS: Recovery of ancestral sequences for transposable elements from the unassembled reads of a whole genome shotgun

    DEFF Research Database (Denmark)

    Li, Ruiqiang; Ye, Jia; Li, Songgang;

    2005-01-01

    in comparison to their ancestral sequences. Tested on the japonica rice genome, ReAS was able to reconstruct all of the high copy sequences in the Repbase repository of known TEs, and increase the effectiveness of RepeatMasker in identifying TEs from genome sequences. Udgivelsesdato: 2005-Sep...

  16. Chloroplast genome sequencing analysis of Heterosigma akashiwo CCMP452 (West Atlantic and NIES293 (West Pacific strains

    Directory of Open Access Journals (Sweden)

    Lybrand Terry

    2008-05-01

    Full Text Available Abstract Background Heterokont algae form a monophyletic group within the stramenopile branch of the tree of life. These organisms display wide morphological diversity, ranging from minute unicells to massive, bladed forms. Surprisingly, chloroplast genome sequences are available only for diatoms, representing two (Coscinodiscophyceae and Bacillariophyceae of approximately 18 classes of algae that comprise this taxonomic cluster. A universal challenge to chloroplast genome sequencing studies is the retrieval of highly purified DNA in quantities sufficient for analytical processing. To circumvent this problem, we have developed a simplified method for sequencing chloroplast genomes, using fosmids selected from a total cellular DNA library. The technique has been used to sequence chloroplast DNA of two Heterosigma akashiwo strains. This raphidophyte has served as a model system for studies of stramenopile chloroplast biogenesis and evolution. Results H. akashiwo strain CCMP452 (West Atlantic chloroplast DNA is 160,149 bp in size with a 21,822-bp inverted repeat, whereas NIES293 (West Pacific chloroplast DNA is 159,370 bp in size and has an inverted repeat of 21,665 bp. The fosmid cloning technique reveals that both strains contain an isomeric chloroplast DNA population resulting from an inversion of their single copy domains. Both strains contain multiple small inverted and tandem repeats, non-randomly distributed within the genomes. Although both CCMP452 and NIES293 chloroplast DNAs contains 197 genes, multiple nucleotide polymorphisms are present in both coding and intergenic regions. Several protein-coding genes contain large, in-frame inserts relative to orthologous genes in other plastids. These inserts are maintained in mRNA products. Two genes of interest in H. akashiwo, not previously reported in any chloroplast genome, include tyrC, a tyrosine recombinase, which we hypothesize may be a result of a lateral gene transfer event, and an

  17. Combined analysis of the chloroplast genome and transcriptome of the Antarctic vascular plant Deschampsia antarctica Desv.

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    Jungeun Lee

    Full Text Available BACKGROUND: Antarctic hairgrass (Deschampsia antarctica Desv. is the only natural grass species in the maritime Antarctic. It has been researched as an important ecological marker and as an extremophile plant for studies on stress tolerance. Despite its importance, little genomic information is available for D. antarctica. Here, we report the complete chloroplast genome, transcriptome profiles of the coding/noncoding genes, and the posttranscriptional processing by RNA editing in the chloroplast system. RESULTS: The complete chloroplast genome of D. antarctica is 135,362 bp in length with a typical quadripartite structure, including the large (LSC: 79,881 bp and small (SSC: 12,519 bp single-copy regions, separated by a pair of identical inverted repeats (IR: 21,481 bp. It contains 114 unique genes, including 81 unique protein-coding genes, 29 tRNA genes, and 4 rRNA genes. Sequence divergence analysis with other plastomes from the BEP clade of the grass family suggests a sister relationship between D. antarctica, Festuca arundinacea and Lolium perenne of the Poeae tribe, based on the whole plastome. In addition, we conducted high-resolution mapping of the chloroplast-derived transcripts. Thus, we created an expression profile for 81 protein-coding genes and identified ndhC, psbJ, rps19, psaJ, and psbA as the most highly expressed chloroplast genes. Small RNA-seq analysis identified 27 small noncoding RNAs of chloroplast origin that were preferentially located near the 5'- or 3'-ends of genes. We also found >30 RNA-editing sites in the D. antarctica chloroplast genome, with a dominance of C-to-U conversions. CONCLUSIONS: We assembled and characterized the complete chloroplast genome sequence of D. antarctica and investigated the features of the plastid transcriptome. These data may contribute to a better understanding of the evolution of D. antarctica within the Poaceae family for use in molecular phylogenetic studies and may also help researchers

  18. Discrete redox signaling pathways regulate photosynthetic light-harvesting and chloroplast gene transcription.

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    John F Allen

    Full Text Available In photosynthesis in chloroplasts, two related regulatory processes balance the actions of photosystems I and II. These processes are short-term, post-translational redistribution of light-harvesting capacity, and long-term adjustment of photosystem stoichiometry initiated by control of chloroplast DNA transcription. Both responses are initiated by changes in the redox state of the electron carrier, plastoquinone, which connects the two photosystems. Chloroplast Sensor Kinase (CSK is a regulator of transcription of chloroplast genes for reaction centres of the two photosystems, and a sensor of plastoquinone redox state. We asked whether CSK is also involved in regulation of absorbed light energy distribution by phosphorylation of light-harvesting complex II (LHC II. Chloroplast thylakoid membranes isolated from a CSK T-DNA insertion mutant and from wild-type Arabidopsis thaliana exhibit similar light- and redox-induced (32P-labelling of LHC II and changes in 77 K chlorophyll fluorescence emission spectra, while room-temperature chlorophyll fluorescence emission transients from Arabidopsis leaves are perturbed by inactivation of CSK. The results indicate indirect, pleiotropic effects of reaction centre gene transcription on regulation of photosynthetic light-harvesting in vivo. A single, direct redox signal is transmitted separately to discrete transcriptional and post-translational branches of an integrated cytoplasmic regulatory system.

  19. Insights into the subunit in-teractions of the chloroplast ATP synthase

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Subunit interactions of the chloroplast F0F1- ATP synthase were studied using the yeast two-hybrid system. The coding sequences of all the nine subunits of spinach chloroplast ATP synthase were cloned in two-hybrid vectors. The vectors were transformed into the yeast strains HF7c and SFY526 by various pairwise combinations, and the protein interactions were analyzed by measuring the yeast growth on minimal SD medium without serine, lucine and histidine. Interactions of γ Subunit with wild type or two truncated mutants of γ sununit, △εN21 and △εC45, which lose their abilities to inhibit the ATP hydrolysis, were also detected by in vitro and in vivo binding assay. The present results are largely accordant to the common structure model of F0F1-ATP synthase. Different from that in the E. Coli F0F1-ATP synthase, the δ subunit of chloroplast ATP syn- thase could interact with β,γ,ε and all the CF0 subunits in the two-hybrid system. These results suggested that though the chloroplast ATP synthase shares the similar structure and composition of subunits with the enzyme from E. Coli, it may be different in the subunit interactions and con- formational change during catalysis between these two sources of ATP synthase. Based on the present results and our knowledge of structure model of E. Coli ATP synthase, a deduced structure model of chloroplast ATP synthase was proposed.

  20. Comparative Analysis of Codon Usage Patterns Among Mitochondrion, Chloroplast and Nuclear Genes in Triticum aestivum L.

    Institute of Scientific and Technical Information of China (English)

    Wen-Juan Zhang; Jie Zhou; Zuo-Feng Li; Li Wang; Xun Gu; Yang Zhong

    2007-01-01

    In many organisms, the difference in codon usage patterns among genes reflects variation in local base compositional biases and the intensity of natural selection. In this study, a comparative analysis was performed to investigate the characteristics of codon bias and factors in shaping the codon usage patterns among mitochondrion,chloroplast and nuclear genes in common wheat (Triticum aestivum L.). GC contents in nuclear genes were higher than that in mitochondrion and chloroplast genes. The neutrality and correspondence analyses indicated that the codon usage in nuclear genes would be a result of relative strong mutational bias, while the codon usage patterns of rnitochondrion and chloroplast genes were more conserved in GC content and influenced by translation level.The Parity Rule 2 (PR2) plot analysis showed that pyrimidines were used more frequently than purines at the third codon position in the three genomes. In addition, using a new alterative strategy, 11, 12, and 24 triplets were defined as preferred codons in the mitochondrion, chloroplast and nuclear genes, respectively. These findings suggested that the mitochondrion, chloroplast and nuclear genes shared particularly different features of codon usage and evolutionary constraints.

  1. The effect of UV-B radiation on chloroplast translation in Pisum sativum

    International Nuclear Information System (INIS)

    UV-B radiation has previously been reported to reduce growth, flowering, and net photosynthesis. The present study examines the effect of UV-B radiation on isolated chloroplast of 7-10 day old pea seedlings. Amount of (3H)-Leu incorporated into isolated chloroplasts was measured in the presence or absence of UV-B exposure. Preliminary experiments show a 30% inhibition of protein synthesis in isolated chloroplasts after only 20 mins of UV-B exposure (6.9 J/m2/30 min). Percent inhibition of chloroplast translation is directly correlated with UV-B exposure over a 60 min time span. Preliminary studies also show no change in both cold and radiolabeled protein profiles as expressed on 1-D PAGE and autofluorography. Comparative studies on the sensitivity of e- flow vs protein synthesis following UV-B exposure are underway. Further work on the role of oxygen free radicals and the specific site of action of UV-B damage to the translation machinery of chloroplasts will be discussed

  2. A Cyan Fluorescent Reporter Expressed from the Chloroplast Genome of Marchantia polymorpha

    Science.gov (United States)

    Boehm, Christian R.; Ueda, Minoru; Nishimura, Yoshiki; Shikanai, Toshiharu; Haseloff, Jim

    2016-01-01

    Recently, the liverwort Marchantia polymorpha has received increasing attention as a basal plant model for multicellular studies. Its ease of handling, well-characterized plastome and proven protocols for biolistic plastid transformation qualify M. polymorpha as an attractive platform to study the evolution of chloroplasts during the transition from water to land. In addition, chloroplasts of M. polymorpha provide a convenient test-bed for the characterization of genetic elements involved in plastid gene expression due to the absence of mechanisms for RNA editing. While reporter genes have proven valuable to the qualitative and quantitative study of gene expression in chloroplasts, expression of green fluorescent protein (GFP) in chloroplasts of M. polymorpha has proven problematic. We report the design of a codon-optimized gfp varian, mturq2cp, which allowed successful expression of a cyan fluorescent protein under control of the tobacco psbA promoter from the chloroplast genome of M. polymorpha. We demonstrate the utility of mturq2cp in (i) early screening for transplastomic events following biolistic transformation of M. polymorpha spores; (ii) visualization of stromules as elements of plastid structure in Marchantia; and (iii) quantitative microscopy for the analysis of promoter activity. PMID:26634291

  3. Proteomic comparison reveals the contribution of chloroplast to salt tolerance of a wheat introgression line.

    Science.gov (United States)

    Xu, Wenjing; Lv, Hongjun; Zhao, Mingming; Li, Yongchao; Qi, Yueying; Peng, Zhenying; Xia, Guangmin; Wang, Mengcheng

    2016-01-01

    We previously bred a salt tolerant wheat cv. SR3 with bread wheat cv. JN177 as the parent via asymmetric somatic hybridization, and found that the tolerance is partially attributed to the superior photosynthesis capacity. Here, we compared the proteomes of two cultivars to unravel the basis of superior photosynthesis capacity. In the maps of two dimensional difference gel electrophoresis (2D-DIGE), there were 26 differentially expressed proteins (DEPs), including 18 cultivar-based and 8 stress-responsive ones. 21 of 26 DEPs were identified and classified into four categories, including photosynthesis, photosynthesis system stability, linolenic acid metabolism, and protein synthesis in chloroplast. The chloroplast localization of some DEPs confirmed that the identified DEPs function in the chloroplast. The overexpression of a DEP enhanced salt tolerance in Arabidopsis thaliana. In line with these data, it is concluded that the contribution of chloroplast to high salinity tolerance of wheat cv. SR3 appears to include higher photosynthesis efficiency by promoting system protection and ROS clearance, stronger production of phytohormone JA by enhancing metabolism activity, and modulating the in chloroplast synthesis of proteins. PMID:27562633

  4. Homologous Comparisons of Photosynthetic System 1 Genes among Cyanobacteria and Chloroplasts

    Institute of Scientific and Technical Information of China (English)

    Jie Yu; Pei-Jun Ma; Ding-Ji Shi; Shi-Ming Li; Chang-Lu Wang

    2008-01-01

    It has now believed that chloroplasts arose from cyanobacteria,however,during endosymbiosis,the photosynthetic genes in chloroplasts have been reduced.How these changes occurred during plant evolution was the focus of the present study.Beginning with photosystem Ⅰ (PSI) genes,a homologous comparison of amino acid sequences of 18 subunits of PSI from 10 species of cyanobacteria,chloroplasts in 12 species of eucaryotic algae,and 28 species of plants (including bryophytes,pteridophytes,gymnospermae,dicotyledon and monocotyledon) was undertaken.The data showed that 18 genes of PSIcan be divided into two groups: Part Ⅰ including seven genes (psaA,psaB,psaC,psaI,psaJ,yct3 and ycf4) shared both by cyanobacteria and plant chloroplasts;Part Ⅱ containing another 11 genes (psaD,psaE,psaF,psaK,psaL,psaM,btpA,ycf37,psaG,psaH and psaN) appeared to have diversified in different plant groups.Among Part I genes,psaC,psaA and psaB had higher homology in all species of cyanobacteria and chloroplasts.Among Part II genes,only psaG,psaH and psaN emerged in seed plants.

  5. Recombination and Heterologous Expression of Allophycocyanin Gene in the Chloroplast of Chlamydomonas reinhardtii

    Institute of Scientific and Technical Information of China (English)

    Zhong-Liang SU; Kai-Xian QIAN; Cong-Ping TAN; Chun-Xiao MENG; Song QIN

    2005-01-01

    Heterogeneous expression of multiple genes in the nucleus of transgenic plants requires the introduction of an individual gene and the subsequent backcross to reconstitute multi-subunit proteins or metabolic pathways. In order to accomplish the expression of multiple genes in a single transformation event, we inserted both large and small subunits of allophycocyanin gene (apcA and apcB) into Chlamydomonas reinhardtii chloroplast expression vector, resulting in papc-S. The constructed vector was then introduced into the chloroplast of C. reinhardtii by micro-particle bombardment. Polymerase chain reaction and Southern blot analysis revealed that the two genes had integrated into the chloroplast genome. Western blot and enzyme-linked immunosorbent assay showed that the two genes from the prokaryotic cyanobacteria could be correctly expressed in the chloroplasts of C. reinhardtii. The expressed foreign protein in transformants accounted for about 2%-3% of total soluble proteins. These findings pave the way to the reconstitution of multi-subunit proteins or metabolic pathways in transgenic C. reinhardtii chloroplasts in a single transformation event.

  6. Construction of a chloroplast protein interaction network and functional mining of photosynthetic proteins in Arabidopsis thaliana

    Institute of Scientific and Technical Information of China (English)

    Qing-Bo Yu; Yong-Lan Cui; Kang Chong; Yi-Xue Li; Yu-Hua Li; Zhongming Zhao; Tie-Liu Shi; Zhong-Nan Yang; Guang Li; Guan Wang; Jing-Chun Sun; Peng-Cheng Wang; Chen Wang; Hua-Ling Mi; Wei-Min Ma; Jian Cui

    2008-01-01

    Chloroplast is a typical plant cell organeUe where photosynthesis takes place.In this study,a total of 1 808 chloroplast core proteins in Arabidopsis thaliana were reliably identified by combining the results of previously published studies and our own predictions.We then constructed a chloroplast protein interaction network primarily based on these core protein interactions.The network had 22 925 protein interaction pairs which involved 2 214 proteins.A total of 160 previously uncharacterized proteins were annotated in this network.The subunits of the photosynthetic complexes were modularized,and the functional relationships among photosystem Ⅰ (PSI),photosystem Ⅱ (PSII),light harvesting complex of photosystem Ⅰ (LHC Ⅰ) and light harvesting complex of photosystem Ⅰ (LHC Ⅱ) could be deduced from the predicted protein interactions in this network.We further confirmed an interaction between an unknown protein AT1G52220 and a photosynthetic subunit PSI-D2 by yeast two-hybrid analysis.Our chloroplast protein interaction network should be useful for functional mining of photosynthetic proteins and investigation of chloroplast-related functions at the systems biology level in Arabidopsis.

  7. Chloroplast lipid transfer processes in Chlamydomonas reinhardtii involving a TRIGALACTOSYLDIACYLGLYCEROL 2 (TGD2) orthologue.

    Science.gov (United States)

    Warakanont, Jaruswan; Tsai, Chia-Hong; Michel, Elena J S; Murphy, George R; Hsueh, Peter Y; Roston, Rebecca L; Sears, Barbara B; Benning, Christoph

    2015-12-01

    In plants, lipids of the photosynthetic membrane are synthesized by parallel pathways associated with the endoplasmic reticulum (ER) and the chloroplast envelope membranes. Lipids derived from the two pathways are distinguished by their acyl-constituents. Following this plant paradigm, the prevalent acyl composition of chloroplast lipids suggests that Chlamydomonas reinhardtii (Chlamydomonas) does not use the ER pathway; however, the Chlamydomonas genome encodes presumed plant orthologues of a chloroplast lipid transporter consisting of TGD (TRIGALACTOSYLDIACYLGLYCEROL) proteins that are required for ER-to-chloroplast lipid trafficking in plants. To resolve this conundrum, we identified a mutant of Chlamydomonas deleted in the TGD2 gene and characterized the respective protein, CrTGD2. Notably, the viability of the mutant was reduced, showing the importance of CrTGD2. Galactoglycerolipid metabolism was altered in the tgd2 mutant with monogalactosyldiacylglycerol (MGDG) synthase activity being strongly stimulated. We hypothesize this to be a result of phosphatidic acid accumulation in the chloroplast outer envelope membrane, the location of MGDG synthase in Chlamydomonas. Concomitantly, increased conversion of MGDG into triacylglycerol (TAG) was observed. This TAG accumulated in lipid droplets in the tgd2 mutant under normal growth conditions. Labeling kinetics indicate that Chlamydomonas can import lipid precursors from the ER, a process that is impaired in the tgd2 mutant. PMID:26496373

  8. A Cyan Fluorescent Reporter Expressed from the Chloroplast Genome of Marchantia polymorpha.

    Science.gov (United States)

    Boehm, Christian R; Ueda, Minoru; Nishimura, Yoshiki; Shikanai, Toshiharu; Haseloff, Jim

    2016-02-01

    Recently, the liverwort Marchantia polymorpha has received increasing attention as a basal plant model for multicellular studies. Its ease of handling, well-characterized plastome and proven protocols for biolistic plastid transformation qualify M. polymorpha as an attractive platform to study the evolution of chloroplasts during the transition from water to land. In addition, chloroplasts of M. polymorpha provide a convenient test-bed for the characterization of genetic elements involved in plastid gene expression due to the absence of mechanisms for RNA editing. While reporter genes have proven valuable to the qualitative and quantitative study of gene expression in chloroplasts, expression of green fluorescent protein (GFP) in chloroplasts of M. polymorpha has proven problematic. We report the design of a codon-optimized gfp varian, mturq2cp, which allowed successful expression of a cyan fluorescent protein under control of the tobacco psbA promoter from the chloroplast genome of M. polymorpha. We demonstrate the utility of mturq2cp in (i) early screening for transplastomic events following biolistic transformation of M. polymorpha spores; (ii) visualization of stromules as elements of plastid structure in Marchantia; and (iii) quantitative microscopy for the analysis of promoter activity. PMID:26634291

  9. Blue-light induced development of chloroplasts in isolated seedling roots

    International Nuclear Information System (INIS)

    Excised roots of pea seedlings (Pisum sativum var. 'Alaska') cultured in a synthetic medium under sterile conditions exhibited differentiation of functional chloroplasts from leucoplasts when irradiated with blue light (350 to 550 nm). This transition was a relatively slow process; nevertheless, the chloroplasts formed in blue light compared very well to leaf chloroplasts as far as micro-structure and photosynthetic activities are concerned. Apparently certain activities of the apical meristem are mandatory in bringing about a transition from leucoplasts to chloroplasts in blue light. After short-time labelling with [3H]uridine the synthesis of plastid ribosomal RNA (rRNA) was studied either during irradiation with blue and red light (600 to 700 nm), respectively, or in darkness. Polyacrylamide gel electrophoresis revealed that in blue light the synthesis of specific chloroplast rRNA species with molecular weights of 1.1 x 106 and 0.56 x 106 daltons was markedly stimulated. In contrast, in dark cultured roots these RNA species were synthesized to a limited extent only whereas the cytoplasmic rRNA species of 1.3 x 106 and 0.7 x 106 daltons molecular weight were preferentially formed. The same held true for roots irradiated with red light. (author)

  10. Polyuridylylation and processing of transcripts from multiple gene minicircles in chloroplasts of the dinoflagellate Amphidinium carterae

    KAUST Repository

    Barbrook, Adrian C.

    2012-05-05

    Although transcription and transcript processing in the chloroplasts of plants have been extensively characterised, the RNA metabolism of other chloroplast lineages across the eukaryotes remains poorly understood. In this paper, we use RT-PCR to study transcription and transcript processing in the chloroplasts of Amphidinium carterae, a model peridinin-containing dinoflagellate. These organisms have a highly unusual chloroplast genome, with genes located on multiple small \\'minicircle\\' elements, and a number of idiosyncratic features of RNA metabolism including transcription via a rolling circle mechanism, and 3′ terminal polyuridylylation of transcripts. We demonstrate that transcription occurs in A. carterae via a rolling circle mechanism, as previously shown in the dinoflagellate Heterocapsa, and present evidence for the production of both polycistronic and monocistronic transcripts from A. carterae minicircles, including several regions containing ORFs previously not known to be expressed. We demonstrate the presence of both polyuridylylated and non-polyuridylylated transcripts in A. carterae, and show that polycistronic transcripts can be terminally polyuridylylated. We present a model for RNA metabolism in dinoflagellate chloroplasts where long polycistronic precursors are processed to form mature transcripts. Terminal polyuridylylation may mark transcripts with the correct 3′ end. © 2012 Springer Science+Business Media B.V.

  11. CHLOROPLAST GENETIC TOOL FOR THE GREEN MICROALGAE HAEMATOCOCCUS PLUVIALIS (CHLOROPHYCEAE, VOLVOCALES)(1).

    Science.gov (United States)

    Gutiérrez, Carla L; Gimpel, Javier; Escobar, Carolina; Marshall, Sergio H; Henríquez, Vitalia

    2012-08-01

    At present, there is strong commercial demand for recombinant proteins, such as antigens, antibodies, biopharmaceuticals, and industrial enzymes, which cannot be fulfilled by existing procedures. Thus, an intensive search for alternative models that may provide efficiency, safety, and quality control is being undertaken by a number of laboratories around the world. The chloroplast of the eukaryotic microalgae Haematococcus pluvialis Flotow has arisen as a candidate for a novel expression platform for recombinant protein production. However, there are important drawbacks that need to be resolved before it can become such a system. The most significant of these are chloroplast genome characterizations, and the development of chloroplast transformation vectors based upon specific endogenous promoters and on homologous targeting regions. In this study, we report the identification and characterization of endogenous chloroplast sequences for use as genetic tools for the construction of H. pluvialis specific expression vectors to efficiently transform the chloroplast of this microalga via microprojectile bombardment. As a consequence, H. pluvialis shows promise as a platform for expressing recombinant proteins for biotechnological applications, for instance, the development of oral vaccines for aquaculture. PMID:27009007

  12. Influence of lanthanum on chloroplast ultrastructure of soybean leaves under ultraviolet-B stress

    Institute of Scientific and Technical Information of China (English)

    PENG Qian; ZHOU Qing

    2009-01-01

    In order to investigate the effects of lanthanum(Ⅲ) on cell ultrastructure of soybean leaves under elevated ultraviolet-B irradiation (UV-B, 280-320 rim), the chloroplast ultrastructure of soybean seedlings was studied by hydroponics under laboratory conditions. The re-sults showed that the thylakoid in chloroplast was orderly and clearly as soybean leaves were pretreated by La(Ⅲ). The thylakoid was indis-tinctly disordered, expanded and even indiscoverable in the chloroplast under UV-B stress. The impact on the thylakoid by the high in-tensity UV-B irradiation (T2) was bigger than that by the low intensity UV-B irradiation (T1). However, the destruction of the chloroplast structure caused by UV-B stress was alleviated by La(Ⅲ), and the arrangement of the thylakoid in the chloroplast became orderly and clearly. The effect of the alleviation by La(Ⅲ) under the low intensity UV-B irradiation (T1) was better than that under the high intensity UV-B irradiation (T2).

  13. Complete chloroplast genome sequence of Omani lime (Citrus aurantiifolia and comparative analysis within the rosids.

    Directory of Open Access Journals (Sweden)

    Huei-Jiun Su

    Full Text Available The genus Citrus contains many economically important fruits that are grown worldwide for their high nutritional and medicinal value. Due to frequent hybridizations among species and cultivars, the exact number of natural species and the taxonomic relationships within this genus are unclear. To compare the differences between the Citrus chloroplast genomes and to develop useful genetic markers, we used a reference-assisted approach to assemble the complete chloroplast genome of Omani lime (C. aurantiifolia. The complete C. aurantiifolia chloroplast genome is 159,893 bp in length; the organization and gene content are similar to most of the rosids lineages characterized to date. Through comparison with the sweet orange (C. sinensis chloroplast genome, we identified three intergenic regions and 94 simple sequence repeats (SSRs that are potentially informative markers with resolution for interspecific relationships. These markers can be utilized to better understand the origin of cultivated Citrus. A comparison among 72 species belonging to 10 families of representative rosids lineages also provides new insights into their chloroplast genome evolution.

  14. The Complete Chloroplast Genome Sequences of the Medicinal Plant Pogostemon cablin.

    Science.gov (United States)

    He, Yang; Xiao, Hongtao; Deng, Cao; Xiong, Liang; Yang, Jian; Peng, Cheng

    2016-01-01

    Pogostemon cablin, the natural source of patchouli alcohol, is an important herb in the Lamiaceae family. Here, we present the entire chloroplast genome of P. cablin. This genome, with 38.24% GC content, is 152,460 bp in length. The genome presents a typical quadripartite structure with two inverted repeats (each 25,417 bp in length), separated by one small and one large single-copy region (17,652 and 83,974 bp in length, respectively). The chloroplast genome encodes 127 genes, of which 107 genes are single-copy, including 79 protein-coding genes, four rRNA genes, and 24 tRNA genes. The genome structure, GC content, and codon usage of this chloroplast genome are similar to those of other species in the family, except that it encodes less protein-coding genes and tRNA genes. Phylogenetic analysis reveals that P. cablin diverged from the Scutellarioideae clade about 29.45 million years ago (Mya). Furthermore, most of the simple sequence repeats (SSRs) are short polyadenine or polythymine repeats that contribute to high AT content in the chloroplast genome. Complete sequences and annotation of P. cablin chloroplast genome will facilitate phylogenic, population and genetic engineering research investigations involving this particular species. PMID:27275817

  15. The Complete Chloroplast Genome Sequences of the Medicinal Plant Pogostemon cablin

    Directory of Open Access Journals (Sweden)

    Yang He

    2016-06-01

    Full Text Available Pogostemon cablin, the natural source of patchouli alcohol, is an important herb in the Lamiaceae family. Here, we present the entire chloroplast genome of P. cablin. This genome, with 38.24% GC content, is 152,460 bp in length. The genome presents a typical quadripartite structure with two inverted repeats (each 25,417 bp in length, separated by one small and one large single-copy region (17,652 and 83,974 bp in length, respectively. The chloroplast genome encodes 127 genes, of which 107 genes are single-copy, including 79 protein-coding genes, four rRNA genes, and 24 tRNA genes. The genome structure, GC content, and codon usage of this chloroplast genome are similar to those of other species in the family, except that it encodes less protein-coding genes and tRNA genes. Phylogenetic analysis reveals that P. cablin diverged from the Scutellarioideae clade about 29.45 million years ago (Mya. Furthermore, most of the simple sequence repeats (SSRs are short polyadenine or polythymine repeats that contribute to high AT content in the chloroplast genome. Complete sequences and annotation of P. cablin chloroplast genome will facilitate phylogenic, population and genetic engineering research investigations involving this particular species.

  16. 周代宗庙礼制考%The Research on the Etiquettes of Zhou Dynasty’s Ancestral Temple

    Institute of Scientific and Technical Information of China (English)

    王启敏

    2015-01-01

    周代社会中与宗庙相关的礼制多种多样。宗庙始成要举行落成典礼,作歌诗以纪之。祭庙的形式可谓五花八门,而且祭者的态度要十分的恭敬、严谨。诸侯有丧事了,要在宗庙吊唁,规矩也很多。此外,如天子即位,天子(或诸侯)娶妻、嫁女、出国、归国、出征、凯旋等都要在宗庙举行郑重的祭告仪式。在宗庙的守护、装饰、迁移等方面,在当时也有着严格的、不同的礼节制度要遵守。%In Zhou dynasty the related ancestral temple customs are various. After the completion of ancestral temple, it should be inaugurated and poems should be made to memorize. The forms of memorial temples are varied. The attitude of the emperor and monarch muse be very respectful. The same was the monarch’s condolences at the ancestral temple. In addition, the ascending to the throne as emperor, or monarch, getting married or married abroad, returning to the homeland and triumphing must be held in the ancestral temple solemnly and be reported to ancestral temple. The temple’s guardian, decoration, migration and the others also have restricted rules to obey.

  17. Towards resolving Lamiales relationships: insights from rapidly evolving chloroplast sequences

    Directory of Open Access Journals (Sweden)

    Heubl Günther

    2010-11-01

    Full Text Available Abstract Background In the large angiosperm order Lamiales, a diverse array of highly specialized life strategies such as carnivory, parasitism, epiphytism, and desiccation tolerance occur, and some lineages possess drastically accelerated DNA substitutional rates or miniaturized genomes. However, understanding the evolution of these phenomena in the order, and clarifying borders of and relationships among lamialean families, has been hindered by largely unresolved trees in the past. Results Our analysis of the rapidly evolving trnK/matK, trnL-F and rps16 chloroplast regions enabled us to infer more precise phylogenetic hypotheses for the Lamiales. Relationships among the nine first-branching families in the Lamiales tree are now resolved with very strong support. Subsequent to Plocospermataceae, a clade consisting of Carlemanniaceae plus Oleaceae branches, followed by Tetrachondraceae and a newly inferred clade composed of Gesneriaceae plus Calceolariaceae, which is also supported by morphological characters. Plantaginaceae (incl. Gratioleae and Scrophulariaceae are well separated in the backbone grade; Lamiaceae and Verbenaceae appear in distant clades, while the recently described Linderniaceae are confirmed to be monophyletic and in an isolated position. Conclusions Confidence about deep nodes of the Lamiales tree is an important step towards understanding the evolutionary diversification of a major clade of flowering plants. The degree of resolution obtained here now provides a first opportunity to discuss the evolution of morphological and biochemical traits in Lamiales. The multiple independent evolution of the carnivorous syndrome, once in Lentibulariaceae and a second time in Byblidaceae, is strongly supported by all analyses and topological tests. The evolution of selected morphological characters such as flower symmetry is discussed. The addition of further sequence data from introns and spacers holds promise to eventually obtain a

  18. Geographic variation of chloroplast DNA in Platycarya strobilacea (Juglandaceae)

    Institute of Scientific and Technical Information of China (English)

    Shi-Chao CHEN; Li ZHANG; Jie ZENG; Fei SHI; Hong YANG; Yun-Rui MAO; Cheng-Xin FU

    2012-01-01

    The monotypic genus Platycarya (Juglandaceae) is one of the most widespread temperate tree species in East Asia.In this research,we implemented a phylogeographical study using chloroplast DNA (cpDNA) (psbA-trnH and atpB-rbcL intergenic spacer) sequences on Platycarya strobilacea,in order to identify the locations of the species' main refugia and migration routes.A total of 180 individuals of P.stobilacea from 27 populations from China and Jeju Island (Korea) were collected.The results revealed that P.strobilacea had 35 haplotypes for the two intergenic spacers and high genetic diversity (hT =0.926).This surprisingly high diversity ofhaplotypes indicates its long evolutionary history,which is in agreement with previous phylogenetic analyses and fossil records.Significant cpDNA population subdivision was detected (GST =0.720; NST =0.862),suggesting low levels of recurrent gene flow through seeds among populations and significant phylogeographical structure (NST > GST,P < 0.05).The construction of phylogenetic relationships of the 35 chlorotypes detected four major cpDNA clades.Divergence dating analyses using BEAST suggest that the divergence of the major cpDNA clades occurred before the Miocene.Demographic analysis indicated that the Eastern clade underwent localized demographic expansions.The molecular phylogenetic data,together with the geographic distribution of the haplotypes,suggest the existence of multiple glacial refugia in most of its current range in China through Quaternary climatic oscillations.

  19. Comparative studies on codon usage pattern of chloroplasts and their host nuclear genes in four plant species

    Indian Academy of Sciences (India)

    Qingpo Liu; Qingzhong Xue

    2005-04-01

    A detailed comparison was made of codon usage of chloroplast genes with their host (nuclear) genes in the four angiosperm species Oryza sativa, Zea mays, Triticum aestivum and Arabidopsis thaliana. The average GC content of the entire genes, and at the three codon positions individually, was higher in nuclear than in chloroplast genes, suggesting different genomic organization and mutation pressures in nuclear and chloroplast genes. The results of Nc-plots and neutrality plots suggested that nucleotide compositional constraint had a large contribution to codon usage bias of nuclear genes in O. sativa, Z. mays, and T. aestivum, whereas natural selection was likely to be playing a large role in codon usage bias in chloroplast genomes. Correspondence analysis and chi-test showed that regardless of the genomic environment (species) of the host, the codon usage pattern of chloroplast genes differed from nuclear genes of their host species by their AU-richness. All the chloroplast genomes have predominantly A- and/or U-ending codons, whereas nuclear genomes have G-, C- or U-ending codons as their optimal codons. These findings suggest that the chloroplast genome might display particular characteristics of codon usage that are different from its host nuclear genome. However, one feature common to both chloroplast and nuclear genomes in this study was that pyrimidines were found more frequently than purines at the synonymous codon position of optimal codons.

  20. The complete chloroplast genome sequence of Lilium hansonii Leichtlin ex D.D.T.Moore.

    Science.gov (United States)

    Kim, Kyunghee; Hwang, Yoon-Jung; Lee, Sang-Choon; Yang, Tae-Jin; Lim, Ki-Byung

    2016-09-01

    Lilium hansonii is a lily species native to Korea and an important wild species for lily breeding. The chloroplast genome of L. hansonii was completed by de novo assembly using the small amount of whole genome sequencing data. The chloroplast genome of L. hansonii was 152 655 bp long and consisted of large single copy region (82 051 bp), small single copy region (17 620 bp) and a pair of inverted repeat regions (26 492 bp). A total of 115 genes were annotated, which included 81 protein-coding genes, 30 tRNA genes and 4 rRNA genes. Phylogenetic analysis with the reported chloroplast genomes revealed that L. hansonii is most closely related to L. superbum (Turk's-cap lily) and L. longiflorum (Easter lily). PMID:26404645

  1. In vitro chloroplast protein synthesis by the chromophytic alga Olisthodiscus luteus

    International Nuclear Information System (INIS)

    The chloroplasts of chlorophytic and chromophytic plants exhibit significant morphological and biochemical differences. Presently, it is impossible to compare the influence of ctDNA on the structure and function of organelles within these two phylogenetic groups for no data exist in the literature on the profile of protein products synthesized by a chromophytic plastid. In this paper, the chloroplast DNA coded proteins of the chromophytic plant Olisthodiscus luteus are investigated by labeling isolated chloroplasts in vitro. Isolated plastids of excellent morphological condition are pulse labeled with [35S]methionine. Approximately 100 proteins are detected by two-dimensional gel electrophoresis and fluorography. However, these isolated plastids have a number of unusual characteristics: (1) they are photosynthetically inactive; (2) in vitro protein synthesis is light independent; (3) all proteins synthesized in vitro are membrane associated

  2. Induction events and short-term regulation of electron transport in chloroplasts: an overview.

    Science.gov (United States)

    Tikhonov, Alexander N

    2015-08-01

    Regulation of photosynthetic electron transport at different levels of structural and functional organization of photosynthetic apparatus provides efficient performance of oxygenic photosynthesis in plants. This review begins with a brief overview of the chloroplast electron transport chain. Then two noninvasive biophysical methods (measurements of slow induction of chlorophyll a fluorescence and EPR signals of oxidized P700 centers) are exemplified to illustrate the possibility of monitoring induction events in chloroplasts in vivo and in situ. Induction events in chloroplasts are considered and briefly discussed in the context of short-term mechanisms of the following regulatory processes: (i) pH-dependent control of the intersystem electron transport; (ii) the light-induced activation of the Calvin-Benson cycle; (iii) optimization of electron transport due to fitting alternative pathways of electron flow and partitioning light energy between photosystems I and II; and (iv) the light-induced remodeling of photosynthetic apparatus and thylakoid membranes. PMID:25680580

  3. The complete chloroplast genome sequence of the medicinal plant Rheum palmatum L. (Polygonaceae).

    Science.gov (United States)

    Fan, Kai; Sun, Xiao-Jie; Huang, Min; Wang, Xu-Mei

    2016-07-01

    The complete chloroplast genome of the medicinal plant Rheum palmatum L. (Polygonaceae) has been reconstructed from the whole-genome Illumina sequencing data. The genome is 161 541 bp in length, and exhibits a typical quadripartite structure of the large (LSC, 86 518 bp) and small (SSC, 13 111 bp) single-copy regions, separated by a pair of inverted repeats (IRs, 30 956 bp each). The chloroplast genome contains 131 genes, including 84 protein-coding genes (78 PCG species), eight ribosomal RNA genes (four rRNA species) and 37 transfer RNA genes (28 tRNA species). Phylogenetic tree based on the maximum parsimony (MP) analysis of 65 chloroplast protein-coding genes for 13 taxa demonstrated a close relationship between R. palmatum and Fagopyrum esculentum subsp. ancestrale in Polygonaceae. PMID:26153751

  4. Metabolic engineering of chloroplasts for artemisinic acid biosynthesis and impact on plant growth

    Indian Academy of Sciences (India)

    Bhawna Saxena; Mayavan Subramaniyan; Karan Malhotra; Neel Sarovar Bhavesh; Shobha Devi Potlakayala; Shashi Kumar

    2014-03-01

    Chloroplasts offer high-level transgene expression and transgene containment due to maternal inheritance, and are ideal hosts for biopharmaceutical biosynthesis via multigene engineering. To exploit these advantages, we have expressed 12 enzymes in chloroplasts for the biosynthesis of artemisinic acid (precursor of artemisinin, antimalarial drug) in an alternative plant system. Integration of transgenes into the tobacco chloroplast genome via homologous recombination was confirmed by molecular analysis, and biosynthesis of artemisinic acid in plant leaf tissues was detected with the help of 13C NMR and ESI-mass spectrometry. The excess metabolic flux of isopentenyl pyrophosphate generated by an engineered mevalonate pathway was diverted for the biosynthesis of artemisinic acid. However, expression of megatransgenes impacted the growth of the transplastomic plantlets. By combining two exogenous pathways, artemisinic acid was produced in transplastomic plants, which can be improved further using better metabolic engineering strategies for commercially viable yield of desirable isoprenoid products.

  5. Identification of the 64 kilodalton chloroplast stromal phosphoprotein as phosphoglucomutase. [Pisum sativum

    Energy Technology Data Exchange (ETDEWEB)

    Salvucci, M.E.; Drake, R.R.; Broadbent, K.P.; Haley, B.E. (Univ. of Kentucky, Lexington (USA)); Hanson, K.R.; McHale, N.A. (Connecticut Agricultural Experiment Station, New Haven, CT (USA))

    1990-05-01

    Phosphorylation of the 64 kilodalton stromal phosphoprotein by incubation of pea (Pisum sativum) chloroplast extracts with ({gamma}-{sup 32}P)ATP decreased in the presence of Glc-6-P and Glc-1,6-P{sub 2}, but was stimulated by glucose. Two-dimensional gel electrophoresis following incubation of intact chloroplasts and stromal extracts with ({gamma}-{sup 32}P)ATP, or incubation of stromal extracts and partially purified phosphoglucomutase (EC 2.7.5.1) with ({sup 32}P)Glc-1-P showed that the identical 64 kilodalton polypeptide was labeled. A 62 kilodalton polypeptide was phosphorylated by incubation of tobacco (Nicotiana sylvestris) stromal extracts with either ({gamma}-{sup 32}P)ATP or ({sup 32}P)Glc-1-P. In contrast, an analogous polypeptide was not phosphorylated in extracts from a tobacco mutant deficient in plastid phosphoglucomutase activity. The results indicate that the 64 (or 62) kilodalton chloroplast stromal phosphoprotein is phosphoglucomutase.

  6. The complete sequence of the chloroplast genome of the green microalga Lobosphaera (Parietochloris) incisa.

    Science.gov (United States)

    Tourasse, Nicolas J; Barbi, Tommaso; Waterhouse, Janet C; Shtaida, Nastassia; Leu, Stefan; Boussiba, Sammy; Purton, Saul; Vallon, Olivier

    2016-05-01

    We hereby report the complete chloroplast genome sequence of the green unicellular alga Lobosphaera (Parietochloris) incisa (strain SAG 2468). The genome consists of a circular chromosome of 156,028 bp, which is 72% A-T rich and does not contain a large rRNA-encoding inverted repeat. It is predicted to encode a total of 111 genes including 78 protein-coding, three rRNA, and 30 tRNA genes. The genome sequence also carries a self-splicing group I intron and a group II intron remnant. Overall, the gene and intron content of the L. incisa chloroplast genome is highly similar to that of other species of Trebouxiophyceae. In contrast, the L. incisa chloroplast genome harbors 88 copies of various intergenic dispersed DNA repeat sequences that are all unique to L. incisa. PMID:25423517

  7. Evolution from the prokaryotic to the higher plant chloroplast signal recognition particle

    DEFF Research Database (Denmark)

    Träger, Chantal; Rosenblad, Magnus Alm; Ziehe, Dominik;

    2012-01-01

    the conserved SRP54 and the SRP receptor, FtsY, are present in higher plant chloroplasts. In this study, we analyzed the phylogenetic distribution of SRP components in photosynthetic organisms to elucidate the evolution of the SRP system. We identified conserved plastid SRP RNAs within all...... data lead to the view that the P. patens cpSRP system occupies an intermediate position in the evolution from bacterial-type SRP to higher plant-type cpSRP system.......The protein targeting signal recognition particle (SRP) pathway in chloroplasts of higher plants has undergone dramatic evolutionary changes. It disposed of its RNA, which is an essential SRP component in bacteria, and uses a unique chloroplast-specific protein cpSRP43. Nevertheless, homologs of...

  8. Phylogenomic analysis of transcriptomic sequences of mitochondria and chloroplasts of essential brown algae (Phaeophyceae) in China

    Institute of Scientific and Technical Information of China (English)

    JIA Shangang; LIU Tao; WU Shuangxiu; WANG Xumin; LI Tianyong; QIAN Hao; SUN Jing; WANG Liang; YU Jun; REN Lufeng; YIN Jinlong

    2014-01-01

    The chloroplast and mitochondrion of brown algae (Class Phaeophyceae of Phylum Ochrophyta) may have originated from different endosymbiosis. In this study, we carried out phylogenomic analysis to distinguish their evolutionary lineages by using algal RNA-seq datasets of the 1 000 Plants (1KP) Project and publicly available complete genomes of mitochondria and chloroplasts of Kingdom Chromista. We have found that there is a split between Class Phaeophyceae of Phylum Ochrophyta and the others (Phylum Cryptophyta and Haptophyta) in Kingdom Chromista, and identified more diversity in chloroplast genes than mitochondrial ones in their phylogenetic trees. Taxonomy resolution for Class Phaeophyceae showed that it was divided into Laminariales-Ectocarpales clade and Fucales clade, and phylogenetic positions of Kjellmaniella crassi-folia, Hizikia fusifrome and Ishige okamurai were confirmed. Our analysis provided the basic phylogenetic relationships of Chromista algae, and demonstrated their potential ability to study endosymbiotic events.

  9. Analysis on the reconstruction accuracy of the Fitch method for inferring ancestral states

    Directory of Open Access Journals (Sweden)

    Grünewald Stefan

    2011-01-01

    Full Text Available Abstract Background As one of the most widely used parsimony methods for ancestral reconstruction, the Fitch method minimizes the total number of hypothetical substitutions along all branches of a tree to explain the evolution of a character. Due to the extensive usage of this method, it has become a scientific endeavor in recent years to study the reconstruction accuracies of the Fitch method. However, most studies are restricted to 2-state evolutionary models and a study for higher-state models is needed since DNA sequences take the format of 4-state series and protein sequences even have 20 states. Results In this paper, the ambiguous and unambiguous reconstruction accuracy of the Fitch method are studied for N-state evolutionary models. Given an arbitrary phylogenetic tree, a recurrence system is first presented to calculate iteratively the two accuracies. As complete binary tree and comb-shaped tree are the two extremal evolutionary tree topologies according to balance, we focus on the reconstruction accuracies on these two topologies and analyze their asymptotic properties. Then, 1000 Yule trees with 1024 leaves are generated and analyzed to simulate real evolutionary scenarios. It is known that more taxa not necessarily increase the reconstruction accuracies under 2-state models. The result under N-state models is also tested. Conclusions In a large tree with many leaves, the reconstruction accuracies of using all taxa are sometimes less than those of using a leaf subset under N-state models. For complete binary trees, there always exists an equilibrium interval [a, b] of conservation probability, in which the limiting ambiguous reconstruction accuracy equals to the probability of randomly picking a state. The value b decreases with the increase of the number of states, and it seems to converge. When the conservation probability is greater than b, the reconstruction accuracies of the Fitch method increase rapidly. The reconstruction

  10. Eleven ancestral gene families lost in mammals and vertebrates while otherwise universally conserved in animals

    Directory of Open Access Journals (Sweden)

    Danchin Etienne GJ

    2006-01-01

    Full Text Available Abstract Background Gene losses played a role which may have been as important as gene and genome duplications and rearrangements, in modelling today species' genomes from a common ancestral set of genes. The set and diversity of protein-coding genes in a species has direct output at the functional level. While gene losses have been reported in all the major lineages of the metazoan tree of life, none have proposed a focus on specific losses in the vertebrates and mammals lineages. In contrast, genes lost in protostomes (i.e. arthropods and nematodes but still present in vertebrates have been reported and extensively detailed. This probable over-anthropocentric way of comparing genomes does not consider as an important phenomena, gene losses in species that are usually described as "higher". However reporting universally conserved genes throughout evolution that have recently been lost in vertebrates and mammals could reveal interesting features about the evolution of our genome, particularly if these losses can be related to losses of capability. Results We report 11 gene families conserved throughout eukaryotes from yeasts (such as Saccharomyces cerevisiae to bilaterian animals (such as Drosophila melanogaster or Caenorhabditis elegans. This evolutionarily wide conservation suggests they were present in the last common ancestors of fungi and metazoan animals. None of these 11 gene families are found in human nor mouse genomes, and their absence generally extends to all vertebrates. A total of 8 out of these 11 gene families have orthologs in plants, suggesting they were present in the Last Eukaryotic Common Ancestor (LECA. We investigated known functional information for these 11 gene families. This allowed us to correlate some of the lost gene families to loss of capabilities. Conclusion Mammalian and vertebrate genomes lost evolutionary conserved ancestral genes that are probably otherwise not dispensable in eukaryotes. Hence, the human

  11. Elongation Factor-Tu (EF-Tu) proteins structural stability and bioinformatics in ancestral gene reconstruction

    Science.gov (United States)

    Dehipawala, Sunil; Nguyen, A.; Tremberger, G.; Cheung, E.; Schneider, P.; Lieberman, D.; Holden, T.; Cheung, T.

    2013-09-01

    A paleo-experimental evolution report on elongation factor EF-Tu structural stability results has provided an opportunity to rewind the tape of life using the ancestral protein sequence reconstruction modeling approach; consistent with the book of life dogma in current biology and being an important component in the astrobiology community. Fractal dimension via the Higuchi fractal method and Shannon entropy of the DNA sequence classification could be used in a diagram that serves as a simple summary. Results from biomedical gene research provide examples on the diagram methodology. Comparisons between biomedical genes such as EEF2 (elongation factor 2 human, mouse, etc), WDR85 in epigenetics, HAR1 in human specificity, DLG1 in cognitive skill, and HLA-C in mosquito bite immunology with EF Tu DNA sequences have accounted for the reported circular dichroism thermo-stability data systematically; the results also infer a relatively less volatility geologic time period from 2 to 3 Gyr from adaptation viewpoint. Comparison to Thermotoga maritima MSB8 and Psychrobacter shows that Thermus thermophilus HB8 EF-Tu calibration sequence could be an outlier, consistent with free energy calculation by NUPACK. Diagram methodology allows computer simulation studies and HAR1 shows about 0.5% probability from chimp to human in terms of diagram location, and SNP simulation results such as amoebic meningoencephalitis NAF1 suggest correlation. Extensions to the studies of the translation and transcription elongation factor sequences in Megavirus Chiliensis, Megavirus Lba and Pandoravirus show that the studied Pandoravirus sequence could be an outlier with the highest fractal dimension and lowest entropy, as compared to chicken as a deviant in the DNMT3A DNA methylation gene sequences from zebrafish to human and to the less than one percent probability in computer simulation using the HAR1 0.5% probability as reference. The diagram methodology would be useful in ancestral gene

  12. Slugs' last meals: molecular identification of sequestered chloroplasts from different algal origins in Sacoglossa (Opisthobranchia, Gastropoda).

    Science.gov (United States)

    Händeler, Katharina; Wägele, Heike; Wahrmund, Ute; Rüdinger, Mareike; Knoop, Volker

    2010-11-01

    Some sacoglossan sea slugs have become famous for their unique capability to extract and incorporate functional chloroplasts from algal food organisms (mainly Ulvophyceae) into their gut cells. The functional incorporation of the so-called kleptoplasts allows the slugs to rely on photosynthetic products for weeks to months, enabling them to survive long periods of food shortage over most of their life-span. The algal food spectrum providing kleptoplasts as temporary, non-inherited endosymbionts appears to vary among sacoglossan slugs, but detailed knowledge is sketchy or unavailable. Accurate identification of algal donor species, which provide the chloroplasts for long-term retention is of primary importance to elucidate the biochemical mechanisms allowing long-term functionality of the captured chloroplast in the foreign animal cell environment. Whereas some sacoglossans forage on a variety of algal species, (e.g. Elysia crispata and E. viridis) others are more selective. Hence, characterizing the range of functional sacoglossan-chloroplast associations in nature is a prerequisite to understand the basis of this enigmatic endosymbiosis. Here, we present a suitable chloroplast gene (tufA) as a marker, which allows identification of the respective algal kleptoplast donor taxa by analysing DNA from whole animals. This novel approach allows identification of donor algae on genus or even species level, thus providing evidence for the taxonomic range of food organisms. We report molecular evidence that chloroplasts from different algal sources are simultaneously incorporated in some species of Elysia. NeigborNet analyses for species assignments are preferred over tree reconstruction methods because the former allow more reliable statements on species identification via barcoding, or rather visualize alternative allocations not to be seen in the latter. PMID:21565106

  13. Endosymbiotic origin and codon bias of the nuclear gene for chloroplast glyceraldehyde-3-phosphate dehydrogenase from maize.

    Science.gov (United States)

    Brinkmann, H; Martinez, P; Quigley, F; Martin, W; Cerff, R

    1987-01-01

    The nuclei of plant cells harbor genes for two types of glyceraldehyde-3-phosphate dehydrogenases (GAPDH) displaying a sequence divergence corresponding to the prokaryote/eukaryote separation. This strongly supports the endosymbiotic theory of chloroplast evolution and in particular the gene transfer hypothesis suggesting that the gene for the chloroplast enzyme, initially located in the genome of the endosymbiotic chloroplast progenitor, was transferred during the course of evolution into the nuclear genome of the endosymbiotic host. Codon usage in the gene for chloroplast GAPDH of maize is radically different from that employed by present-day chloroplasts and from that of the cytosolic (glycolytic) enzyme from the same cell. This reveals the presence of subcellular selective pressures which appear to be involved in the optimization of gene expression in the economically important graminaceous monocots. PMID:3131533

  14. Photoregulation of fructose and glucose respiration in the intact chloroplasts of Chlamydomonas reinhardtii F-60 and spinach

    International Nuclear Information System (INIS)

    The photoregulation of chloroplastic respiration was studied by monitoring in darkness and in light the release of 14CO2 from whole chloroplasts of Chlamydomonas reinhardtii F-60 and spinach (Spinacia oleracea L.) supplied externally with [14C]glucose and [14C]fructose, respectively. CO2 release was inhibited more than 90% in both chloroplasts by a light intensity of 4 W m-2. Oxidants, oxaloacetate in Chlamydomonas, nitrite in spinach, and phenazine methosulfate in both chloroplasts, reversed the inhibition. The onset of the photoinhibitory effect on CO2 release was relatively rapid compared to the restoration of CO2 release following illumination. In both darkened chloroplasts, dithiothreitol inhibited release. Of the four enzymes (fructokinase, phosphoglucose isomerase, glucose-6-P dehydrogenase, and gluconate-6-P dehydrogenase) in the pathway catalyzing the release of CO2 from fructose, only glucose-6-P dehydrogenase was deactivated by light and by dithiothreitol. 33 refs., 3 figs., 4 tabs

  15. Spectral characteristics and orientation of native forms of pigment in chloroplasts of barley seedlings under intermittent and continuous irradiation

    International Nuclear Information System (INIS)

    Chorophyll (Chl) form at 710-712 nm localized on the small protein simultaneously connected with the reaction centre of photosystem 1 (RC PS1) and the light-harvesting complex I (LHC-I) polypeptides is supposed to be the source of long-wavelength band of low-temperature fluorescence of chloroplasts at 735-740 nm. Chloroplasts of intermittently irradiated seedlings (or chloroplasts of the Chl b-less barley mutant) did not differ from chloroplasts of continuously irradiated seedlings (or chloroplasts of wild type barley) in the set of Chl a and beta-carotene forms and their orientation in the membrane. A competition for the newly synthesized Chl a molecules occurred between the RC PS 2 and LHC-II polypeptides

  16. Proton Gradients and Proton-Dependent Transport Processes in the Chloroplast

    OpenAIRE

    Höhner, Ricarda; Aboukila, Ali; Kunz, Hans-Henning; Venema, Kees

    2016-01-01

    Proton gradients are fundamental to chloroplast function. Across thylakoid membranes, the light induced -proton gradient is essential for ATP synthesis. As a result of proton pumping into the thylakoid lumen, an alkaline stromal pH develops, which is required for full activation of pH-dependent Calvin Benson cycle enzymes. This implies that a pH gradient between the cytosol (pH 7) and the stroma (pH 8) is established upon illumination. To maintain this pH gradient chloroplasts actively extrud...

  17. Multiple regulatory mechanisms in the chloroplast of green algae: relation to hydrogen production.

    Science.gov (United States)

    Antal, Taras K; Krendeleva, Tatyana E; Tyystjärvi, Esa

    2015-09-01

    A complex regulatory network in the chloroplast of green algae provides an efficient tool for maintenance of energy and redox balance in the cell under aerobic and anaerobic conditions. In this review, we discuss the structural and functional organizations of electron transport pathways in the chloroplast, and regulation of photosynthesis in the green microalga Chlamydomonas reinhardtii. The focus is on the regulatory mechanisms induced in response to nutrient deficiency stress and anoxia and especially on the role of a hydrogenase-mediated reaction in adaptation to highly reducing conditions and ATP deficiency in the cell. PMID:25986411

  18. The complete chloroplast genome sequence of Tetrastigma hemsleyanum Diels at Gilg.

    Science.gov (United States)

    Li, Mengzhu; Chen, Qinyi; Yang, Bingxian; Ma, Ji; Li, Baoguo; Zhang, Lin

    2016-09-01

    The complete chloroplast genome sequence of Tetrastigma hemsleyanum Diels at Gilg, a critical Chinese medicine, is reported here. The complete chloroplast genome of Tetrastigma hemsleyanum Diels at Gilg is 159 914 bp in length with 37.55% overall GC content. A pair of IRs (inverted repeats) of 26 510 bp were separated by LSC (87 927 bp) and SSC (18 967 bp). The phylogenetic analysis of 40 taxa showed a strong sister relationship with all other rosids. However, the placement of Myrtales still needs further verification. PMID:26329851

  19. Evolutionary, Molecular and Genetic Analyses of Tic22 Homologues in Arabidopsis thaliana Chloroplasts

    OpenAIRE

    Kasmati, Ali Reza; Töpel, Mats; Khan, Nadir Zaman; Patel, Ramesh; Ling, Qihua; Karim, Sazzad; Aronsson, Henrik; Jarvis, Paul

    2013-01-01

    The Tic22 protein was previously identified in pea as a putative component of the chloroplast protein import apparatus. It is a peripheral protein of the inner envelope membrane, residing in the intermembrane space. In Arabidopsis, there are two Tic22 homologues, termed atTic22-III and atTic22-IV, both of which are predicted to localize in chloroplasts. These two proteins defined clades that are conserved in all land plants, which appear to have evolved at a similar rates since their separati...

  20. Derived immune and ancestral pigmentation alleles in a 7,000-year-old Mesolithic European.

    Science.gov (United States)

    Olalde, Iñigo; Allentoft, Morten E; Sánchez-Quinto, Federico; Santpere, Gabriel; Chiang, Charleston W K; DeGiorgio, Michael; Prado-Martinez, Javier; Rodríguez, Juan Antonio; Rasmussen, Simon; Quilez, Javier; Ramírez, Oscar; Marigorta, Urko M; Fernández-Callejo, Marcos; Prada, María Encina; Encinas, Julio Manuel Vidal; Nielsen, Rasmus; Netea, Mihai G; Novembre, John; Sturm, Richard A; Sabeti, Pardis; Marquès-Bonet, Tomàs; Navarro, Arcadi; Willerslev, Eske; Lalueza-Fox, Carles

    2014-03-13

    Ancient genomic sequences have started to reveal the origin and the demographic impact of farmers from the Neolithic period spreading into Europe. The adoption of farming, stock breeding and sedentary societies during the Neolithic may have resulted in adaptive changes in genes associated with immunity and diet. However, the limited data available from earlier hunter-gatherers preclude an understanding of the selective processes associated with this crucial transition to agriculture in recent human evolution. Here we sequence an approximately 7,000-year-old Mesolithic skeleton discovered at the La Braña-Arintero site in León, Spain, to retrieve a complete pre-agricultural European human genome. Analysis of this genome in the context of other ancient samples suggests the existence of a common ancient genomic signature across western and central Eurasia from the Upper Paleolithic to the Mesolithic. The La Braña individual carries ancestral alleles in several skin pigmentation genes, suggesting that the light skin of modern Europeans was not yet ubiquitous in Mesolithic times. Moreover, we provide evidence that a significant number of derived, putatively adaptive variants associated with pathogen resistance in modern Europeans were already present in this hunter-gatherer. PMID:24463515

  1. Major Chromosomal Rearrangements Distinguish Willow and Poplar After the Ancestral "Salicoid" Genome Duplication.

    Science.gov (United States)

    Hou, Jing; Ye, Ning; Dong, Zhongyuan; Lu, Mengzhu; Li, Laigeng; Yin, Tongming

    2016-01-01

    Populus (poplar) and Salix (willow) are sister genera in the Salicaceae family. In both lineages extant species are predominantly diploid. Genome analysis previously revealed that the two lineages originated from a common tetraploid ancestor. In this study, we conducted a syntenic comparison of the corresponding 19 chromosome members of the poplar and willow genomes. Our observations revealed that almost every chromosomal segment had a parallel paralogous segment elsewhere in the genomes, and the two lineages shared a similar syntenic pinwheel pattern for most of the chromosomes, which indicated that the two lineages diverged after the genome reorganization in the common progenitor. The pinwheel patterns showed distinct differences for two chromosome pairs in each lineage. Further analysis detected two major interchromosomal rearrangements that distinguished the karyotypes of willow and poplar. Chromosome I of willow was a conjunction of poplar chromosome XVI and the lower portion of poplar chromosome I, whereas willow chromosome XVI corresponded to the upper portion of poplar chromosome I. Scientists have suggested that Populus is evolutionarily more primitive than Salix. Therefore, we propose that, after the "salicoid" duplication event, fission and fusion of the ancestral chromosomes first give rise to the diploid progenitor of extant Populus species. During the evolutionary process, fission and fusion of poplar chromosomes I and XVI subsequently give rise to the progenitor of extant Salix species. This study contributes to an improved understanding of genome divergence after ancient genome duplication in closely related lineages of higher plants. PMID:27352946

  2. Transgenerational actions of environmental compounds on reproductive disease and identification of epigenetic biomarkers of ancestral exposures.

    Directory of Open Access Journals (Sweden)

    Mohan Manikkam

    Full Text Available Environmental factors during fetal development can induce a permanent epigenetic change in the germ line (sperm that then transmits epigenetic transgenerational inheritance of adult-onset disease in the absence of any subsequent exposure. The epigenetic transgenerational actions of various environmental compounds and relevant mixtures were investigated with the use of a pesticide mixture (permethrin and insect repellant DEET, a plastic mixture (bisphenol A and phthalates, dioxin (TCDD and a hydrocarbon mixture (jet fuel, JP8. After transient exposure of F0 gestating female rats during the period of embryonic gonadal sex determination, the subsequent F1-F3 generations were obtained in the absence of any environmental exposure. The effects on the F1, F2 and F3 generations pubertal onset and gonadal function were assessed. The plastics, dioxin and jet fuel were found to promote early-onset female puberty transgenerationally (F3 generation. Spermatogenic cell apoptosis was affected transgenerationally. Ovarian primordial follicle pool size was significantly decreased with all treatments transgenerationally. Differential DNA methylation of the F3 generation sperm promoter epigenome was examined. Differential DNA methylation regions (DMR were identified in the sperm of all exposure lineage males and found to be consistent within a specific exposure lineage, but different between the exposures. Several genomic features of the DMR, such as low density CpG content, were identified. Exposure-specific epigenetic biomarkers were identified that may allow for the assessment of ancestral environmental exposures associated with adult onset disease.

  3. Evidence from cyclostomes for complex regionalization of the ancestral vertebrate brain.

    Science.gov (United States)

    Sugahara, Fumiaki; Pascual-Anaya, Juan; Oisi, Yasuhiro; Kuraku, Shigehiro; Aota, Shin-ichi; Adachi, Noritaka; Takagi, Wataru; Hirai, Tamami; Sato, Noboru; Murakami, Yasunori; Kuratani, Shigeru

    2016-03-01

    The vertebrate brain is highly complex, but its evolutionary origin remains elusive. Because of the absence of certain developmental domains generally marked by the expression of regulatory genes, the embryonic brain of the lamprey, a jawless vertebrate, had been regarded as representing a less complex, ancestral state of the vertebrate brain. Specifically, the absence of a Hedgehog- and Nkx2.1-positive domain in the lamprey subpallium was thought to be similar to mouse mutants in which the suppression of Nkx2-1 leads to a loss of the medial ganglionic eminence. Here we show that the brain of the inshore hagfish (Eptatretus burgeri), another cyclostome group, develops domains equivalent to the medial ganglionic eminence and rhombic lip, resembling the gnathostome brain. Moreover, further investigation of lamprey larvae revealed that these domains are also present, ruling out the possibility of convergent evolution between hagfish and gnathostomes. Thus, brain regionalization as seen in crown gnathostomes is not an evolutionary innovation of this group, but dates back to the latest vertebrate ancestor before the divergence of cyclostomes and gnathostomes more than 500 million years ago. PMID:26878236

  4. WEB LOG PREPROCESSING BASED ON PARTIAL ANCESTRAL GRAPH TECHNIQUE FOR SESSION CONSTRUCTION

    Directory of Open Access Journals (Sweden)

    S.Chitra

    2012-10-01

    Full Text Available Web access log analysis is to analyze the patterns of web site usage and the features of users behavior. It is the fact that the normal Log data is very noisy and unclear and it is vital to preprocess the log data for efficient web usage mining process. Preprocessing comprises of three phases which includes data cleaning, user identification and session construction. Session construction is very vital and numerous real world problems can be modeled as traversals on graph and mining from these traversals would provide the requirement for preprocessing phase. On the other hand, the traversals on unweighted graph have been taken into consideration in existing works. This paper oversimplifies this to the case where vertices of graph are given weights to reflect their significance. The proposed method constructs sessions as a Partial Ancestral Graph which contains pages with calculated weights. This will help site administrators to find the interesting pages for users and to redesign their web pages. After weighting each page according to browsing time a PAG structure is constructed for each user session. Existing system in which there is a problem of learning with the latent variables of the data and the problem can be overcome by the proposed method.

  5. The ancestral circadian clock of monarch butterflies: role in time-compensated sun compass orientation.

    Science.gov (United States)

    Reppert, S M

    2007-01-01

    The circadian clock has a vital role in monarch butterfly (Danaus plexippus) migration by providing the timing component of time-compensated sun compass orientation, which contributes to navigation to the overwintering grounds. The location of circadian clock cells in monarch brain has been identified in the dorsolateral protocerebrum (pars lateralis); these cells express PERIOD, TIMELESS, and a Drosophila-like cryptochrome designated CRY1. Monarch butterflies, like all other nondrosophilid insects examined so far, express a second cry gene (designated insect CRY2) that encodes a vertebrate-like CRY that is also expressed in pars lateralis. An ancestral circadian clock mechanism has been defined in monarchs, in which CRY1 functions as a blue light photoreceptor for photic entrainment, whereas CRY2 functionswithin the clockwork as themajor transcriptional repressor of an intracellular negative transcriptional feedback loop. A CRY1-staining neural pathway has been identified that may connect the circadian (navigational) clock to polarized light input important for sun compass navigation, and a CRY2-positive neural pathway has been discovered that may communicate circadian information directly from the circadian clock to the central complex, the likely site of the sun compass. The monarch butterfly may thus use the CRY proteins as components of the circadian mechanism and also as output molecules that connect the clock to various aspects of the sun compass apparatus. PMID:18419268

  6. Detection of Weakly Conserved Ancestral Mammalian RegulatorySequences by Primate Comparisons

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Qian-fei; Prabhakar, Shyam; Chanan, Sumita; Cheng,Jan-Fang; Rubin, Edward M.; Boffelli, Dario

    2006-06-01

    Genomic comparisons between human and distant, non-primatemammals are commonly used to identify cis-regulatory elements based onconstrained sequence evolution. However, these methods fail to detectcryptic functional elements, which are too weakly conserved among mammalsto distinguish from nonfunctional DNA. To address this problem, weexplored the potential of deep intra-primate sequence comparisons. Wesequenced the orthologs of 558 kb of human genomic sequence, coveringmultiple loci involved in cholesterol homeostasis, in 6 nonhumanprimates. Our analysis identified 6 noncoding DNA elements displayingsignificant conservation among primates, but undetectable in more distantcomparisons. In vitro and in vivo tests revealed that at least three ofthese 6 elements have regulatory function. Notably, the mouse orthologsof these three functional human sequences had regulatory activity despitetheir lack of significant sequence conservation, indicating that they arecryptic ancestral cis-regulatory elements. These regulatory elementscould still be detected in a smaller set of three primate speciesincluding human, rhesus and marmoset. Since the human and rhesus genomesequences are already available, and the marmoset genome is activelybeing sequenced, the primate-specific conservation analysis describedhere can be applied in the near future on a whole-genome scale, tocomplement the annotation provided by more distant speciescomparisons.

  7. The vomeronasal complex of nocturnal strepsirhines and implications for the ancestral condition in primates.

    Science.gov (United States)

    Garrett, Eva C; Dennis, John C; Bhatnagar, Kunwar P; Durham, Emily L; Burrows, Anne M; Bonar, Christopher J; Steckler, Natalie K; Morrison, Edward E; Smith, Timothy D

    2013-12-01

    This study investigates the vomeronasal organ in extant nocturnal strepsirhines as a model for ancestral primates. Cadaveric samples from 10 strepsirhine species, ranging from fetal to adult ages, were studied histologically. Dimensions of structures in the vomeronasal complex, such as the vomeronasal neuroepithelium (VNNE) and vomeronasal cartilage (VNC) were measured in serial sections and selected specimens were studied immunohistochemically to determine physiological aspects of the vomeronasal sensory neurons (VSNs). Osteological features corresponding to vomeronasal structures were studied histologically and related to 3-D CT reconstructions. The VNC consistently rests in a depression on the palatal portion of the maxilla, which we refer to as the vomeronasal groove (VNG). Most age comparisons indicate that in adults VNNE is about twice the length compared with perinatal animals. In VNNE volume, adults are 2- to 3-fold larger compared with perinatal specimens. Across ages, a strong linear relationship exists between VNNE dimensions and body length, mass, and midfacial length. Results indicate that the VNNE of nocturnal strepsirhines is neurogenic postnatally based on GAP43 expression. In addition, based on Olfactory Marker Protein expression, terminally differentiated VSNs are present in the VNNE. Therefore, nocturnal strepsirhines have basic similarities to rodents in growth and maturational characteristics of VSNs. These results indicate that a functional vomeronasal system is likely present in all nocturnal strepsirhines. Finally, given that osteological features such as the VNG are visible on midfacial bones, primate fossils can be assessed to determine whether primate ancestors possessed a vomeronasal complex morphologically similar to that of modern nocturnal strepsirhines. PMID:24249398

  8. Major Chromosomal Rearrangements Distinguish Willow and Poplar After the Ancestral “Salicoid” Genome Duplication

    Science.gov (United States)

    Hou, Jing; Ye, Ning; Dong, Zhongyuan; Lu, Mengzhu; Li, Laigeng; Yin, Tongming

    2016-01-01

    Populus (poplar) and Salix (willow) are sister genera in the Salicaceae family. In both lineages extant species are predominantly diploid. Genome analysis previously revealed that the two lineages originated from a common tetraploid ancestor. In this study, we conducted a syntenic comparison of the corresponding 19 chromosome members of the poplar and willow genomes. Our observations revealed that almost every chromosomal segment had a parallel paralogous segment elsewhere in the genomes, and the two lineages shared a similar syntenic pinwheel pattern for most of the chromosomes, which indicated that the two lineages diverged after the genome reorganization in the common progenitor. The pinwheel patterns showed distinct differences for two chromosome pairs in each lineage. Further analysis detected two major interchromosomal rearrangements that distinguished the karyotypes of willow and poplar. Chromosome I of willow was a conjunction of poplar chromosome XVI and the lower portion of poplar chromosome I, whereas willow chromosome XVI corresponded to the upper portion of poplar chromosome I. Scientists have suggested that Populus is evolutionarily more primitive than Salix. Therefore, we propose that, after the “salicoid” duplication event, fission and fusion of the ancestral chromosomes first give rise to the diploid progenitor of extant Populus species. During the evolutionary process, fission and fusion of poplar chromosomes I and XVI subsequently give rise to the progenitor of extant Salix species. This study contributes to an improved understanding of genome divergence after ancient genome duplication in closely related lineages of higher plants. PMID:27352946

  9. A PCA-based method for ancestral informative markers selection in structured populations

    Institute of Scientific and Technical Information of China (English)

    ZHANG Feng; ZHANG Lei; DENG Hong-Wen

    2009-01-01

    Identification of population structure can help trace population histories and identify disease genes.Structured association (SA) is a commonly used approach for population structure identification and association mapping. A major issue with SA is that its performance greatly depends on the informativeness and the numbers of ancestral informative markers (AIMs). Present major AIM selection methods mostly require prior individual ancestry information, which is usually not available or uncertain in practice. To address this potential weakness, we herein develop a novel approach for AIM selection based on principle component analysis (PCA), which does not require prior ancestry information of study subjects. Our simulation and real genetic data analysis results suggest that, with equivalent AIMs,PCA-based selected AIMs can significantly increase the accuracy of inferred individual ancestries compared with traditionally randomly selected AIMs. Our method can easily be applied to whole genome data to select a set of highly informative AIMs in population structure, which can then be used to identify potential population structure and correct possible statistical biases caused by population stratification.

  10. The hypothetical ancestral animal. the Urmetazoa: telomerase activity in sponges (Porifera

    Directory of Open Access Journals (Sweden)

    ISABEL M. MÜLLER

    2003-05-01

    Full Text Available Sponges (Porifera represent the lowest metazoan phylum, characterized by a pronounced plasticity in the determination of cell lineages, and they are the closest related taxon to the hypothetical ancestral animal, the Urmetazoa, from which the metazoan lineages diverged. In a first approach to elucidate the molecular mechanisms controlling the switch from the cell lineage with a putative indefinite growth capacity to senescent, somatic cells, the activity of the telomerase as an indicator for immortality has been determined. The studies were performed with the marine demosponges Suberites domuncula and Geodia cydonium, in vivo with tissue but also in vitro using the primmorph system. Primmorphs are formed from dissociated cells which have retained their proliferation potency. It was found that the activity of telomerase in tissue of both sponges is high. Based on this and additional findings it is assumed that the separation of the senescent sponge cell lineage from the immortal germ-/somatic cell lineage is triggered by the loss of contact to cell adhesion factors. First evidence is included which suggests that the final progress of the senescent, telomerase-negative cells to cell death is caused by apoptosis.

  11. Evolutionary Psychology: How Psychological Mechanisms Shaped by Natural Selection for Ancestral Environments Produce Current Behaviours

    Institute of Scientific and Technical Information of China (English)

    Charles Crawford

    2009-01-01

    The central purpose of this paper is to explain how Darwin's theory of evolution by natural selection can be used in understanding current human behaviour. First, Darwin's logic is briefly described. Development is an important issue when applying evolutionary theory to human behaviour. The notion of innate developmental orga-nization of psychological mechanisms is introduced. The possible social and political outcomes produced when differ-ent levels of innate developmental organization are paired with different beliefs about it are considered. The notion of psychological mechanisms as evolved adaptations is considered in some detail. Then I discuss different ways evo-htionists think about how genes are involved in the development of adaptations. The paper concludes with a frame-work for considering how ancestral adaptations function in current environments and outlines some ways of studying them. In China and many other parts of the world people desire a more harmonious society. Ⅰ hope that this paper will be of some small help in achieving this great task.

  12. A PCA-based method for ancestral informative markers selection in structured populations

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Identification of population structure can help trace population histories and identify disease genes. Structured association (SA) is a commonly used approach for population structure identification and association mapping. A major issue with SA is that its performance greatly depends on the informa-tiveness and the numbers of ancestral informative markers (AIMs). Present major AIM selection meth-ods mostly require prior individual ancestry information, which is usually not available or uncertain in practice. To address this potential weakness, we herein develop a novel approach for AIM selection based on principle component analysis (PCA), which does not require prior ancestry information of study subjects. Our simulation and real genetic data analysis results suggest that, with equivalent AIMs, PCA-based selected AIMs can significantly increase the accuracy of inferred individual ancestries compared with traditionally randomly selected AIMs. Our method can easily be applied to whole genome data to select a set of highly informative AIMs in population structure, which can then be used to identify potential population structure and correct possible statistical biases caused by population stratification.

  13. Inheritance of the 8.1 ancestral haplotype in recurrent pregnancy loss

    DEFF Research Database (Denmark)

    Kolte, Astrid M; Nielsen, Henriette S; Steffensen, Rudi;

    2015-01-01

    BACKGROUND AND OBJECTIVES: The 8.1 ancestral haplotype (AH) (HLA-A1, C7, B8, C4AQ0, C4B1, DR3, DQ2) is a remarkably long and conserved haplotype in the human major histocompatibility complex. It has been associated with both beneficial and detrimental effects, consistent with antagonistic....... The objective was to test the gestational drive theory for the 8.1AH in women with RPL and their live born children. METHODOLOGY: We investigated the inheritance of the 8.1AH from 82 heterozygous RPL women to 110 live born children. All participants were genotyped for HLA-A, -B and -DRB1 in DNA from...... EDTA-treated blood or buccal swaps. Inheritance was compared with a Mendelian inheritance of 50% using a two-sided exact binomial test. RESULTS: We found that 55% of the live born children had inherited the 8.1AH, which was not significantly higher than the expected 50% (P = 0.29). Interestingly, we...

  14. Identification of the ancestral haplotype for apolipoprotein B suggests an African origin of Homo sapiens sapiens and traces their subsequent migration to Europe and the Pacific

    International Nuclear Information System (INIS)

    The probable ancestral haplotype for human apolipoprotein B (apoB) has been identified through immunological analysis of chimpanzee and gorilla serum and sequence analysis of their DNA. Moreover, the frequency of this ancestral apoB haplotype among different human populations provides strong support for the African origin of Homo sapiens sapiens and their subsequent migration from Africa to Europe and to the Pacific. The approach used here for the identification of the ancestral human apoB haplotype is likely to be applicable to many other genes

  15. Identification of the ancestral haplotype for apolipoprotein B suggests an African origin of Homo sapiens sapiens and traces their subsequent migration to Europe and the Pacific

    Energy Technology Data Exchange (ETDEWEB)

    Rapacz, J.; Hasler-Rapacz, J.O. (Univ. of Wisconsin, Madison (United States)); Chen, L.; Wu, Mingjiuan; Schumaker, V.N. (Univ. of California, Los Angeles (United States)); Butler-Brunner, E.; Butler, R. (Swiss Red Cross Blood Transfusion Service, Bern (Switzerland))

    1991-02-15

    The probable ancestral haplotype for human apolipoprotein B (apoB) has been identified through immunological analysis of chimpanzee and gorilla serum and sequence analysis of their DNA. Moreover, the frequency of this ancestral apoB haplotype among different human populations provides strong support for the African origin of Homo sapiens sapiens and their subsequent migration from Africa to Europe and to the Pacific. The approach used here for the identification of the ancestral human apoB haplotype is likely to be applicable to many other genes.

  16. The Crystal Structure of Aq_328 from the Hyperthermophilic Bacteria Aquifex aeolicus Shows an Ancestral Histone Fold

    OpenAIRE

    Qiu, Yang; Tereshko, Valentina; Kim, Youngchang; Zhang, Rongguang; Collart, Frank; Yousef, Mohammed; Kossiakoff, Anthony; Joachimiak, Andrzej

    2006-01-01

    The structure of Aq_328, an uncharacterized protein from hyperthermophilic bacteria Aquifex aeolicus, has been determined to 1.9 Å by using multi-wavelength anomalous diffraction (MAD) phasing. Although the amino acid sequence analysis shows that Aq_328 has no significant similarity to proteins with a known structure and function, the structure comparison by using the Dali server reveals that it: (1) assumes a histone-like fold, and (2) is similar to an ancestral nuclear histone protein (PDB ...

  17. Genotype-based ancestral background consistently predicts efficacy and side effects across treatments in CATIE and STAR*D.

    Directory of Open Access Journals (Sweden)

    Daniel E Adkins

    Full Text Available Only a subset of patients will typically respond to any given prescribed drug. The time it takes clinicians to declare a treatment ineffective leaves the patient in an impaired state and at unnecessary risk for adverse drug effects. Thus, diagnostic tests robustly predicting the most effective and safe medication for each patient prior to starting pharmacotherapy would have tremendous clinical value. In this article, we evaluated the use of genetic markers to estimate ancestry as a predictive component of such diagnostic tests. We first estimated each patient's unique mosaic of ancestral backgrounds using genome-wide SNP data collected in the Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE (n = 765 and the Sequenced Treatment Alternatives to Relieve Depression (STAR*D (n = 1892. Next, we performed multiple regression analyses to estimate the predictive power of these ancestral dimensions. For 136/89 treatment-outcome combinations tested in CATIE/STAR*D, results indicated 1.67/1.84 times higher median test statistics than expected under the null hypothesis assuming no predictive power (p<0.01, both samples. Thus, ancestry showed robust and pervasive correlations with drug efficacy and side effects in both CATIE and STAR*D. Comparison of the marginal predictive power of MDS ancestral dimensions and self-reported race indicated significant improvements to model fit with the inclusion of MDS dimensions, but mixed evidence for self-reported race. Knowledge of each patient's unique mosaic of ancestral backgrounds provides a potent immediate starting point for developing algorithms identifying the most effective and safe medication for a wide variety of drug-treatment response combinations. As relatively few new psychiatric drugs are currently under development, such personalized medicine offers a promising approach toward optimizing pharmacotherapy for psychiatric conditions.

  18. Genetic evidence for the ancestral loss of short-wavelength-sensitive cone pigments in mysticete and odontocete cetaceans.

    OpenAIRE

    Levenson, D H; Dizon, A

    2003-01-01

    All mammals ancestrally possessed two types of cone pigments, an arrangement that persists in nearly all contemporary species. However, the absence of one of these cone types, the short-wavelength-sensitive (SWS) cone, has recently been established in several delphinoid cetacean species, indicating that the loss of this pigment type may be widespread among cetaceans. To evaluate the functional condition of SWS cones in cetaceans, partial SWS cone-opsin gene sequences were obtained from nuclea...

  19. Effect of the assignment of ancestral CpG state on the estimation of nucleotide substitution rates in mammals

    Directory of Open Access Journals (Sweden)

    Keightley Peter D

    2008-09-01

    Full Text Available Abstract Background Molecular evolutionary studies in mammals often estimate nucleotide substitution rates within and outside CpG dinucleotides separately. Frequently, in alignments of two sequences, the division of sites into CpG and non-CpG classes is based simply on the presence or absence of a CpG dinucleotide in either sequence, a procedure that we refer to as CpG/non-CpG assignment. Although it likely that this procedure is biased, it is generally assumed that the bias is negligible if species are very closely related. Results Using simulations of DNA sequence evolution we show that assignment of the ancestral CpG state based on the simple presence/absence of the CpG dinucleotide can seriously bias estimates of the substitution rate, because many true non-CpG changes are misassigned as CpG. Paradoxically, this bias is most severe between closely related species, because a minimum of two substitutions are required to misassign a true ancestral CpG site as non-CpG whereas only a single substitution is required to misassign a true ancestral non-CpG site as CpG in a two branch tree. We also show that CpG misassignment bias differentially affects fourfold degenerate and noncoding sites due to differences in base composition such that fourfold degenerate sites can appear to be evolving more slowly than noncoding sites. We demonstrate that the effects predicted by our simulations occur in a real evolutionary setting by comparing substitution rates estimated from human-chimp coding and intronic sequence using CpG/non-CpG assignment with estimates derived from a method that is largely free from bias. Conclusion Our study demonstrates that a common method of assigning sites into CpG and non CpG classes in pairwise alignments is seriously biased and recommends against the adoption of ad hoc methods of ancestral state assignment.

  20. Impacts of Plant-Based Foods in Ancestral Hominin Diets on the Metabolism and Function of Gut Microbiota In Vitro

    OpenAIRE

    Gary S Frost; Walton, Gemma E; Jonathan R Swann; Psichas, Arianna; Costabile, Adele; Johnson, Laura P.; Sponheimer, Matt; Glenn R Gibson; Barraclough, Timothy G.

    2014-01-01

    ABSTRACT Ancestral human populations had diets containing more indigestible plant material than present-day diets in industrialized countries. One hypothesis for the rise in prevalence of obesity is that physiological mechanisms for controlling appetite evolved to match a diet with plant fiber content higher than that of present-day diets. We investigated how diet affects gut microbiota and colon cells by comparing human microbial communities with those from a primate that has an extreme plan...

  1. Impacts of plant-based foods in ancestral hominin diets on the metabolism and function of gut microbiota in vitro

    OpenAIRE

    Gary S Frost; Gemma E Walton; Swann, Jonathan R.; Psichas, Arianna; Costabile, Adele; Laura P. Johnson; Sponheimer, Matt; Glenn R Gibson; Barraclough, Timothy G.

    2014-01-01

    Ancestral human populations had diets containing more indigestible plant material than present-day diets in industrialized countries. One hypothesis for the rise in prevalence of obesity is that physiological mechanisms for controlling appetite evolved to match a diet with plant fiber content higher than that of present-day diets. We investigated how diet affects gut microbiota and colon cells by comparing human microbial communities with those from a primate that has an extreme plant-based d...

  2. A chloroplast genealogy of hordeum (poaceae): Long-term persisting haplotypes, incomplete lineage sorting, regional extinction, and the consequences for phylogenetic inference.

    Science.gov (United States)

    Jakob, Sabine S; Blattner, Frank R

    2006-08-01

    To analyze reasons for inconclusive results of earlier chloroplast phylogenies in the grass genus Hordeum, we established a genealogy of chloroplast haplotypes by sequencing the trnL-trnF region in 875 individuals, covering all 31 species of the genus. Although the outcomes of phenetic and parsimony analyses of 88 haplotypes were ambiguous, a network approach showed that in Hordeum ancient chloroplast types co-occur with their descendants. Moreover, we found up to 18 different chloroplast haplotypes within a single species and up to 6 species sharing single haplotypes. Persisting polymorphisms together with incomplete lineage sorting occurred preferentially in the rapidly speciating New World taxa of the genus, where ancient chloroplast types have survived for at least 4 Myr. Lineages-through-time plots and a high number of missing chloroplast haplotypes indicated far-reaching extinction of chloroplast lineages in Europe and particularly the Mediterranean. Survival of these lineages in East Asia and North America resulted in chloroplast relationships that markedly differed from nuclear estimations of species relationships. Thus, even for the deepest splits in the genus, reaching back more than 9 Myr, no safe phylogenetic inference from chloroplast data is possible in Hordeum. The chloroplast genealogy, however, revealed biogeographic patterns and indicated processes involved in speciation in Hordeum. We conclude that the described phenomena are not restricted to Hordeum and that the knowledge of the chloroplast relationships within a genus is indispensable to prevent misinterpretation of phylogeographic data within single species. PMID:16754643

  3. Structure of the ATP synthase from chloroplasts studied by electron microscopy and image processing

    NARCIS (Netherlands)

    Boekema, Egbert J.; Heel, Marin van; Gräber, Peter

    1988-01-01

    The structure of the hydrophilic part of the ATP synthase from chloroplasts (CF1) has been investigated by electron microscopy of negatively stained samples. The staining conditions, which are generally critical for such small objects as CF1, could be improved by mixing CF1 samples with a much large

  4. Structure of the ATP synthase from chloroplasts studied by electron microscopy. Localization of the small subunits

    NARCIS (Netherlands)

    Boekema, Egbert J.; Xiao, Jianping; McCarty, Richard E.

    1990-01-01

    The structure of the hydrophilic part of the ATP synthase from chloroplasts (CF1) has been further investigated by electron microscopy and image analysis of negatively stained samples. The projections of three different types of CF1 were analyzed: the holoenzyme with five different subunits and two

  5. Role of membrane glycerolipids in photosynthesis, thylakoid biogenesis and chloroplast development.

    Science.gov (United States)

    Kobayashi, Koichi

    2016-07-01

    The lipid bilayer of the thylakoid membrane in plant chloroplasts and cyanobacterial cells is predominantly composed of four unique lipid classes; monogalactosyldiacylglycerol (MGDG), digalactosyldiacylglycerol (DGDG), sulfoquinovosyldiacylglycerol (SQDG) and phosphatidylglycerol (PG). MGDG and DGDG are uncharged galactolipids that constitute the bulk of thylakoid membrane lipids and provide a lipid bilayer matrix for photosynthetic complexes as the main constituents. The glycolipid SQDG and phospholipid PG are anionic lipids with a negative charge on their head groups. SQDG and PG substitute for each other to maintain the amount of total anionic lipids in the thylakoid membrane, with PG having indispensable functions in photosynthesis. In addition to biochemical studies, extensive analyses of mutants deficient in thylakoid lipids have revealed important roles of these lipids in photosynthesis and thylakoid membrane biogenesis. Moreover, recent studies of Arabidopsis thaliana suggest that thylakoid lipid biosynthesis triggers the expression of photosynthesis-associated genes in both the nucleus and plastids and activates the formation of photosynthetic machineries and chloroplast development. Meanwhile, galactolipid biosynthesis is regulated in response to chloroplast functionality and lipid metabolism at transcriptional and post-translational levels. This review summarizes the roles of thylakoid lipids with their biosynthetic pathways in plants and discusses the coordinated regulation of thylakoid lipid biosynthesis with the development of photosynthetic machinery during chloroplast biogenesis. PMID:27114097

  6. Cowpea chloroplastic ATP synthase is the source of multiple plant defense elicitors during insect herbivory

    Science.gov (United States)

    Plant responses to damage vary dependant upon the nature of the biotic and abiotic stresses. We recently described an elicitor, from Fall armyworm (Spodoptera frugiperda) oral secretions (OS) termed inceptin, derived from chloroplastic ATP synthase '-subunit (cATPC) proteins that activate phytohormo...

  7. Chloroplast evolution in the Pinus montezumae complex: a coalescent approach to hybridization.

    Science.gov (United States)

    Matos, J A; Schaal, B A

    2000-08-01

    This study addresses the evolutionary history of the chloroplast genomes of two closely related pine species, Pinus hartwegii Lindl. and P. montezumae Lamb (subsect. Ponderosae) using coalescent theory and some of the statistical tools that have been developed from it during the past two decades. Pinus hartwegii and P. montezumae are closely related species in the P. montezumae complex (subsect. Ponderosae) of Mexico and Central America. Pinus hartwegii is a high elevation species, whereas P. montezumae occurs at lower elevations. The two species occur on many of the same mountains throughout Mexico. A total of 350 individuals of P. hartwegii and P. montezumae were collected from Nevado de Colima (Jalisco), Cerro Potosí (Nuevo León), Iztaccihuatl/Popocatepetl (México), and Nevado de Toluca (México). The chloroplast genome of P. hartwegii and P. montezumae was mapped using eight restriction enzymes. Fifty-one different haplotypes were characterized; 38 of 160 restriction sites were polymorphic. Clades of most parsimoniously related chloroplast haplotypes are geographically localized and do not overlap in distribution, and the geographically localized clades of haplotypes include both P. hartwegii and P. montezumae. Some haplotypes in the clades occur in only one of the two species, whereas other haplotypes occur in both species. These data strongly suggest ancient and/or ongoing hybridization between P. hartwegii and P. montezumae and a shared chloroplast genome history within geographic regions of Mexico. PMID:11005290

  8. Expression patterns of cotton chloroplast genes during development: implications for development of plastid transformation vectors

    Science.gov (United States)

    In order to express genes of interest in plastids, transformation vectors must be developed that include appropriate promoters to drive expression at effective levels in both green and non-green tissues. Typically, chloroplasts are transformed with vectors that contain ribosomal RNA promoters for h...

  9. A tiling microarray for global analysis of chloroplast genome expression in cucumber and other plants

    Directory of Open Access Journals (Sweden)

    Pląder Wojciech

    2011-09-01

    Full Text Available Abstract Plastids are small organelles equipped with their own genomes (plastomes. Although these organelles are involved in numerous plant metabolic pathways, current knowledge about the transcriptional activity of plastomes is limited. To solve this problem, we constructed a plastid tiling microarray (PlasTi-microarray consisting of 1629 oligonucleotide probes. The oligonucleotides were designed based on the cucumber chloroplast genomic sequence and targeted both strands of the plastome in a non-contiguous arrangement. Up to 4 specific probes were designed for each gene/exon, and the intergenic regions were covered regularly, with 70-nt intervals. We also developed a protocol for direct chemical labeling and hybridization of as little as 2 micrograms of chloroplast RNA. We used this protocol for profiling the expression of the cucumber chloroplast plastome on the PlasTi-microarray. Owing to the high sequence similarity of plant plastomes, the newly constructed microarray can be used to study plants other than cucumber. Comparative hybridization of chloroplast transcriptomes from cucumber, Arabidopsis, tomato and spinach showed that the PlasTi-microarray is highly versatile.

  10. Chloroplast DNA variation of oaks in western Central Europe and genetic consequences of human influences

    NARCIS (Netherlands)

    König, A.O.; Ziegenhagen, B.; Dam, van B.C.; Csaikl, U.M.; Coart, E.; Degen, B.; Burg, K.; Vries, de S.M.G.; Petit, R.J.

    2002-01-01

    Oak chloroplast DNA (cpDNA) variation was studied in a grid-based inventory in western Central Europe, including Belgium, The Netherlands, Luxembourg, Germany, the Czech Republic, and the northern parts of Upper and Lower Austria. A total of 2155 trees representing 426 populations of Quercus robur L

  11. Ion Channels in Plant Bioenergetic Organelles, Chloroplasts and Mitochondria: From Molecular Identification to Function.

    Science.gov (United States)

    Carraretto, Luca; Teardo, Enrico; Checchetto, Vanessa; Finazzi, Giovanni; Uozumi, Nobuyuki; Szabo, Ildiko

    2016-03-01

    Recent technical advances in electrophysiological measurements, organelle-targeted fluorescence imaging, and organelle proteomics have pushed the research of ion transport a step forward in the case of the plant bioenergetic organelles, chloroplasts and mitochondria, leading to the molecular identification and functional characterization of several ion transport systems in recent years. Here we focus on channels that mediate relatively high-rate ion and water flux and summarize the current knowledge in this field, focusing on targeting mechanisms, proteomics, electrophysiology, and physiological function. In addition, since chloroplasts evolved from a cyanobacterial ancestor, we give an overview of the information available about cyanobacterial ion channels and discuss the evolutionary origin of chloroplast channels. The recent molecular identification of some of these ion channels allowed their physiological functions to be studied using genetically modified Arabidopsis plants and cyanobacteria. The view is emerging that alteration of chloroplast and mitochondrial ion homeostasis leads to organelle dysfunction, which in turn significantly affects the energy metabolism of the whole organism. Clear-cut identification of genes encoding for channels in these organelles, however, remains a major challenge in this rapidly developing field. Multiple strategies including bioinformatics, cell biology, electrophysiology, use of organelle-targeted ion-sensitive probes, genetics, and identification of signals eliciting specific ion fluxes across organelle membranes should provide a better understanding of the physiological role of organellar channels and their contribution to signaling pathways in plants in the future. PMID:26751960

  12. Chloroplast β chaperonins from A. thaliana function with endogenous cpn10 homologs in vitro.

    Science.gov (United States)

    Vitlin, Anna; Weiss, Celeste; Demishtein-Zohary, Keren; Rasouly, Aviram; Levin, Doron; Pisanty-Farchi, Odelia; Breiman, Adina; Azem, Abdussalam

    2011-09-01

    The involvement of type I chaperonins in bacterial and organellar protein folding has been well-documented. In E. coli and mitochondria, these ubiquitous and highly conserved proteins form chaperonin oligomers of identical 60 kDa subunits (cpn60), while in chloroplasts, two distinct cpn60 α and β subunit types co-exist together. The primary sequence of α and β subunits is ~50% identical, similar to their respective homologies to the bacterial GroEL. Moreover, the A. thaliana genome contains two α and four β genes. The functional significance of this variability in plant chaperonin proteins has not yet been elucidated. In order to gain insight into the functional variety of the chloroplast chaperonin family members, we reconstituted β homo-oligomers from A. thaliana following their expression in bacteria and subjected them to a structure-function analysis. Our results show for the first time, that A. thaliana β homo-oligomers can function in vitro with authentic chloroplast co-chaperonins (ch-cpn10 and ch-cpn20). We also show that oligomers made up of different β subunit types have unique properties and different preferences for co-chaperonin partners. We propose that chloroplasts may contain active β homo-oligomers in addition to hetero-oligomers, possibly reflecting a variety of cellular roles. PMID:21633907

  13. The complete chloroplast genome sequence of Ledebouriella seseloides (Hoffm.) H. Wolff.

    Science.gov (United States)

    Lee, Hyun Oh; Kim, Kyunghee; Lee, Sang-Choon; Lee, Junki; Lee, Jonghoon; Kim, Soonok; Yang, Tae-Jin

    2016-09-01

    Ledebouriella seseloides (Hoffm.) H.Wolff is a traditional medicinal herb belonging to Apiaceae family, whose dried roots and rhizomes have been used as traditional medicine in East Asian countries. The complete chloroplast genome of L. seseloides was obtained by de novo assembly using the small amount of whole genome sequencing data. The chloroplast genome of L. seseloides was 147 880 bp in length, which consisted of large single copy region (93 222 bp), small single copy region (17 324 bp), and a pair of inverted repeat regions (18 667 bp). The overall GC contents of the chloroplast genome were 37.5%. A total of 113 genes were annotated, which included 79 protein-coding genes, 30 tRNA genes, and four rRNA genes. Phylogenetic analysis with the reported chloroplast genomes revealed that L. seseloides is most closely related to Petroselinum crispum (parsley), an herb widely used in cooking. PMID:26218226

  14. Heterologous nuclear and chloroplast microsatellite amplification and variation in tea, Camellia sinensis.

    Science.gov (United States)

    Kaundun, Shiv Shankhar; Matsumoto, Satoru

    2002-12-01

    The advantage of the cross transferability of heterologous chloroplast and nuclear microsatellite primers was taken to detect polymorphism among 24 tea (Camellia sinensis (L.) O. Kuntze) genotypes, including both the assamica and the sinensis varieties. Primer information was obtained from the closely related Camellia japonica species for four nuclear microsatellites, and from Nicotiana tabaccum for seven universal chloroplast microsatellites. All of the nuclear microsatellite loci tested generated an expected DNA fragment in tea, revealing between three and five alleles per locus. Four out of the seven chloroplast microsatellites primers amplified positively, and of these only one was polymorphic with three alleles, which is in agreement with the conserved nature of chloroplast microsatellites at the intraspecific level. A factorial correspondence analysis carried out on all genotypes and nuclear microsatellite alleles separated the assamica and sinensis genotypes into two groups, thus demonstrating the value of these markers in establishing the genetic relationship between tea varieties. Genetic diversity measured with nuclear microsatellites was higher than that measured with other types of molecular markers, offering prospects for their use in fingerprinting, mapping, and population genetic studies, whereas polymorphisms detected at a cpSSR locus will allow the determination of plastid inheritance in the species. PMID:12502248

  15. Chloroplast FtsZ assembles into a contractible ring via tubulin-like heteropolymerization.

    Science.gov (United States)

    Yoshida, Yamato; Mogi, Yuko; TerBush, Allan D; Osteryoung, Katherine W

    2016-01-01

    Chloroplast division is driven by a ring containing FtsZ1 and FtsZ2 proteins, which originated from bacterial FtsZ, a tubulin-like protein; however, mechanistic details of the chloroplast FtsZ ring remain unclear. Here, we report that FtsZ1 and FtsZ2 can heteropolymerize into a contractible ring ex vivo. Fluorescently labelled FtsZ1 and/or FtsZ2 formed single rings in cells of the yeast Pichia pastoris. Photobleaching experiments indicated that co-assembly of FtsZ1 and FtsZ2 imparts polarity to polymerization. Assembly of FtsZ chimaeras revealed that the protofilaments assemble via heteropolymerization of FtsZ2 and FtsZ1. Contraction of the ring was accompanied by an increase in the filament turnover rate. Our findings suggest that the evolutionary duplication of FtsZ in plants may have increased the mobility and kinetics of FtsZ ring dynamics in chloroplast division. Thus, the gene duplication and heteropolymerization of chloroplast FtsZs may represent convergent evolution with eukaryotic tubulin. PMID:27322658

  16. Preparation of intact chloroplasts by chemically induced lysis of the green alga Dunaliella marina.

    Science.gov (United States)

    Kombrink, E; Wöber, G

    1980-07-01

    A method for the isolation in high yield of intact chloroplasts from the unicellular green alga Dunaliella marina (Volvocales) is described. This procedure uses chemically induced lysis of cells with the polycationic macromolecules, DEAE-dextran (M=500,000) or poly-D,L-lysine (M=30,000-70,000). Reaction conditions were optimized with respect to obtaining a high yield of intact chloroplasts, after isopycnic centrifugation in a linear sucrose density gradient, by varying the concentration of polycation and the temperature and pH of incubation. Broken chloroplasts devoid of the stromal marker enzymes fructosebisphosphate phosphatase and ribulosebisphosphate carboxylase, but containing mitochondrial (fumarase) and microbody (catalase) contamination, were banded at a bouyant density of 1.18 g cm(-3). Intact chloroplasts, as indicated by their retention of alkaline fructosebisphosphate phosphatase and ribulosebisphosphate carboxylase, were found in 30% yield (chlorophyll in intact cells, 100%) at an equilibrium density of 1.24 g cm(-3). Contamination by cytoplasmic material (pyruvate kinase), mitochondria, and microbodies was less than 8% each. PMID:24306242

  17. Sequencing of chloroplast genome using whole cellular DNA and Solexa sequencing technology

    Directory of Open Access Journals (Sweden)

    Jian eWu

    2012-11-01

    Full Text Available Sequencing of the chloroplast genome using traditional sequencing methods has been difficult because of its size (>120 kb and the complicated procedures required to prepare templates. To explore the feasibility of sequencing the chloroplast genome using DNA extracted from whole cells and Solexa sequencing technology, we sequenced whole cellular DNA isolated from leaves of three Brassica rapa accessions with one lane per accession. In total, 246 Mb, 362Mb, 361 Mb sequence data were generated for the three accessions Chiifu-401-42, Z16 and FT, respectively. Microreads were assembled by reference-guided assembly using the cpDNA sequences of B. rapa, Arabidopsis thaliana, and Nicotiana tabacum. We achieved coverage of more than 99.96% of the cp genome in the three tested accessions using the B. rapa sequence as the reference. When A. thaliana or N. tabacum sequences were used as references, 99.7–99.8% or 95.5–99.7% of the B. rapa chloroplast genome was covered, respectively. These results demonstrated that sequencing of whole cellular DNA isolated from young leaves using the Illumina Genome Analyzer is an efficient method for high-throughput sequencing of chloroplast genome.

  18. Guard Cell Chloroplasts Are Essential for Blue Light-Dependent Stomatal Opening in Arabidopsis

    Science.gov (United States)

    Suetsugu, Noriyuki; Takami, Tsuneaki; Ebisu, Yuuta; Watanabe, Harutaka; Iiboshi, Chihoko; Doi, Michio; Shimazaki, Ken-ichiro

    2014-01-01

    Blue light (BL) induces stomatal opening through the activation of H+-ATPases with subsequent ion accumulation in guard cells. In most plant species, red light (RL) enhances BL-dependent stomatal opening. This RL effect is attributable to the chloroplasts of guard cell, the only cells in the epidermis possessing this organelle. To clarify the role of chloroplasts in stomatal regulation, we investigated the effects of RL on BL-dependent stomatal opening in isolated epidermis, guard cell protoplasts, and intact leaves of Arabidopsis thaliana. In isolated epidermal tissues and intact leaves, weak BL superimposed on RL enhanced stomatal opening while BL alone was less effective. In guard cell protoplasts, RL enhanced BL-dependent H+-pumping and DCMU, a photosynthetic electron transport inhibitor, eliminated this effect. RL enhanced phosphorylation levels of the H+-ATPase in response to BL, but this RL effect was not suppressed by DCMU. Furthermore, DCMU inhibited both RL-induced and BL-dependent stomatal opening in intact leaves. The photosynthetic rate in leaves correlated positively with BL-dependent stomatal opening in the presence of DCMU. We conclude that guard cell chloroplasts provide ATP and/or reducing equivalents that fuel BL-dependent stomatal opening, and that they indirectly monitor photosynthetic CO2 fixation in mesophyll chloroplasts by absorbing PAR in the epidermis. PMID:25250952

  19. Origins of the amphiploid species Brassica napus L. investigated by chloroplast and nuclear molecular markers

    Directory of Open Access Journals (Sweden)

    Allender Charlotte J

    2010-03-01

    Full Text Available Abstract Background The amphiploid species Brassica napus (oilseed rape, Canola is a globally important oil crop yielding food, biofuels and industrial compounds such as lubricants and surfactants. Identification of the likely ancestors of each of the two genomes (designated A and C found in B. napus would facilitate incorporation of novel alleles from the wider Brassica genepool in oilseed rape crop genetic improvement programmes. Knowledge of the closest extant relatives of the genotypes involved in the initial formation of B. napus would also allow further investigation of the genetic factors required for the formation of a stable amphiploid and permit the more efficient creation of fully fertile re-synthesised B. napus. We have used a combination of chloroplast and nuclear genetic markers to investigate the closest extant relatives of the original maternal progenitors of B. napus. This was based on a comprehensive sampling of the relevant genepools, including 83 accessions of A genome B. rapa L. (both wild and cultivated types, 94 accessions of B. napus and 181 accessions of C genome wild and cultivated B. oleracea L. and related species. Results Three chloroplast haplotypes occurred in B. napus. The most prevalent haplotype (found in 79% of accessions was not present within the C genome accessions but was found at low frequencies in B. rapa. Chloroplast haplotypes characteristic of B. napus were found in a small number of wild and weedy B. rapa populations, and also in two accessions of cultivated B. rapa 'brocoletto'. Whilst introgression of the B. napus chloroplast type in the wild and weedy B. rapa populations has been proposed by other studies, the presence of this haplotype within the two brocoletto accessions is unexplained. Conclusions The distribution of chloroplast haplotypes eliminate any of the C genome species as being the maternal ancestor of the majority of the B. napus accessions. The presence of multiple chloroplast

  20. Are Hox genes ancestrally involved in axial patterning? Evidence from the hydrozoan Clytia hemisphaerica (Cnidaria.

    Directory of Open Access Journals (Sweden)

    Roxane Chiori

    Full Text Available BACKGROUND: The early evolution and diversification of Hox-related genes in eumetazoans has been the subject of conflicting hypotheses concerning the evolutionary conservation of their role in axial patterning and the pre-bilaterian origin of the Hox and ParaHox clusters. The diversification of Hox/ParaHox genes clearly predates the origin of bilaterians. However, the existence of a "Hox code" predating the cnidarian-bilaterian ancestor and supporting the deep homology of axes is more controversial. This assumption was mainly based on the interpretation of Hox expression data from the sea anemone, but growing evidence from other cnidarian taxa puts into question this hypothesis. METHODOLOGY/PRINCIPAL FINDINGS: Hox, ParaHox and Hox-related genes have been investigated here by phylogenetic analysis and in situ hybridisation in Clytia hemisphaerica, an hydrozoan species with medusa and polyp stages alternating in the life cycle. Our phylogenetic analyses do not support an origin of ParaHox and Hox genes by duplication of an ancestral ProtoHox cluster, and reveal a diversification of the cnidarian HOX9-14 genes into three groups called A, B, C. Among the 7 examined genes, only those belonging to the HOX9-14 and the CDX groups exhibit a restricted expression along the oral-aboral axis during development and in the planula larva, while the others are expressed in very specialised areas at the medusa stage. CONCLUSIONS/SIGNIFICANCE: Cross species comparison reveals a strong variability of gene expression along the oral-aboral axis and during the life cycle among cnidarian lineages. The most parsimonious interpretation is that the Hox code, collinearity and conservative role along the antero-posterior axis are bilaterian innovations.

  1. Allelic lineages of the ficolin genes (FCNs are passed from ancestral to descendant primates.

    Directory of Open Access Journals (Sweden)

    Tina Hummelshøj

    Full Text Available The ficolins recognize carbohydrates and acetylated compounds on microorganisms and dying host cells and are able to activate the lectin pathway of the complement system. In humans, three ficolin genes have been identified: FCN1, FCN2 and FCN3, which encode ficolin-1, ficolin-2 and ficolin-3, respectively. Rodents have only two ficolins designated ficolin-A and ficolin-B that are closely related to human ficolin-1, while the rodent FCN3 orthologue is a pseudogene. Ficolin-2 and ficolin-3 have so far only been observed in humans. Thus, we performed a systematic investigation of the FCN genes in non-human primates. The exons and intron-exon boundaries of the FCN1-3 genes were sequenced in the following primate species: chimpanzee, gorilla, orangutan, rhesus macaque, cynomolgus macaque, baboon and common marmoset. We found that the exon organisation of the FCN genes was very similar between all the non-human primates and the human FCN genes. Several variations in the FCN genes were found in more than one primate specie suggesting that they were carried from one species to another including humans. The amino acid diversity of the ficolins among human and non-human primate species was estimated by calculating the Shannon entropy revealing that all three proteins are generally highly conserved. Ficolin-1 and ficolin-2 showed the highest diversity, whereas ficolin-3 was more conserved. Ficolin-2 and ficolin-3 were present in non-human primate sera with the same characteristic oligomeric structures as seen in human serum. Taken together all the FCN genes show the same characteristics in lower and higher primates. The existence of trans-species polymorphisms suggests that different FCN allelic lineages may be passed from ancestral to descendant species.

  2. Placental expression of pituitary hormones is an ancestral feature of therian mammals

    Directory of Open Access Journals (Sweden)

    Menzies Brandon R

    2011-08-01

    Full Text Available Abstract Background The placenta is essential for supplying nutrients and gases to the developing mammalian young before birth. While all mammals have a functional placenta, only in therian mammals (marsupials and eutherians does the placenta closely appose or invade the uterine endometrium. The eutherian placenta secretes hormones that are structurally and functionally similar to pituitary growth hormone (GH, prolactin (PRL and luteinizing hormone (LH. Marsupial and eutherian mammals diverged from a common ancestor approximately 125 to 148 million years ago and developed distinct reproductive strategies. As in eutherians, marsupials rely on a short-lived but functional placenta for embryogenesis. Results We characterized pituitary GH, GH-R, IGF-2, PRL and LHβ in a macropodid marsupial, the tammar wallaby, Macropus eugenii. These genes were expressed in the tammar placenta during the last third of gestation when most fetal growth occurs and active organogenesis is initiated. The mRNA of key growth genes GH, GH-R, IGF-2 and PRL were expressed during late pregnancy. We found significant up-regulation of GH, GH-R and IGF-2 after the start of the rapid growth phase of organogenesis which suggests that the placental growth hormones regulate the rapid phase of fetal growth. Conclusions This is the first demonstration of the existence of pituitary hormones in the marsupial placenta. Placental expression of these pituitary hormones has clearly been conserved in marsupials as in eutherian mammals, suggesting an ancestral origin of the evolution of placental expression and a critical function of these hormones in growth and development of all therian mammals.

  3. An Ancestral Role for CONSTITUTIVE TRIPLE RESPONSE1 Proteins in Both Ethylene and Abscisic Acid Signaling.

    Science.gov (United States)

    Yasumura, Yuki; Pierik, Ronald; Kelly, Steven; Sakuta, Masaaki; Voesenek, Laurentius A C J; Harberd, Nicholas P

    2015-09-01

    Land plants have evolved adaptive regulatory mechanisms enabling the survival of environmental stresses associated with terrestrial life. Here, we focus on the evolution of the regulatory CONSTITUTIVE TRIPLE RESPONSE1 (CTR1) component of the ethylene signaling pathway that modulates stress-related changes in plant growth and development. First, we compare CTR1-like proteins from a bryophyte, Physcomitrella patens (representative of early divergent land plants), with those of more recently diverged lycophyte and angiosperm species (including Arabidopsis [Arabidopsis thaliana]) and identify a monophyletic CTR1 family. The fully sequenced P. patens genome encodes only a single member of this family (PpCTR1L). Next, we compare the functions of PpCTR1L with that of related angiosperm proteins. We show that, like angiosperm CTR1 proteins (e.g. AtCTR1 of Arabidopsis), PpCTR1L modulates downstream ethylene signaling via direct interaction with ethylene receptors. These functions, therefore, likely predate the divergence of the bryophytes from the land-plant lineage. However, we also show that PpCTR1L unexpectedly has dual functions and additionally modulates abscisic acid (ABA) signaling. In contrast, while AtCTR1 lacks detectable ABA signaling functions, Arabidopsis has during evolution acquired another homolog that is functionally distinct from AtCTR1. In conclusion, the roles of CTR1-related proteins appear to have functionally diversified during land-plant evolution, and angiosperm CTR1-related proteins appear to have lost an ancestral ABA signaling function. Our study provides new insights into how molecular events such as gene duplication and functional differentiation may have contributed to the adaptive evolution of regulatory mechanisms in plants. PMID:26243614

  4. Identification of the ancestral killer immunoglobulin-like receptor gene in primates

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    Coggill Penny

    2006-08-01

    Full Text Available Abstract Background Killer Immunoglobulin-like Receptors (KIR are essential immuno-surveillance molecules. They are expressed on natural killer and T cells, and interact with human leukocyte antigens. KIR genes are highly polymorphic and contribute vital variability to our immune system. Numerous KIR genes, belonging to five distinct lineages, have been identified in all primates examined thus far and shown to be rapidly evolving. Since few KIR remain orthologous between species, with only one of them, KIR2DL4, shown to be common to human, apes and monkeys, the evolution of the KIR gene family in primates remains unclear. Results Using comparative analyses, we have identified the ancestral KIR lineage (provisionally named KIR3DL0 in primates. We show KIR3DL0 to be highly conserved with the identification of orthologues in human (Homo sapiens, common chimpanzee (Pan troglodytes, gorilla (Gorilla gorilla, rhesus monkey (Macaca mulatta and common marmoset (Callithrix jacchus. We predict KIR3DL0 to encode a functional molecule in all primates by demonstrating expression in human, chimpanzee and rhesus monkey. Using the rhesus monkey as a model, we further show the expression profile to be typical of KIR by quantitative measurement of KIR3DL0 from an enriched population of natural killer cells. Conclusion One reason why KIR3DL0 may have escaped discovery for so long is that, in human, it maps in between two related leukocyte immunoglobulin-like receptor clusters outside the known KIR gene cluster on Chromosome 19. Based on genomic, cDNA, expression and phylogenetic data, we report a novel lineage of immunoglobulin receptors belonging to the KIR family, which is highly conserved throughout 50 million years of primate evolution.

  5. The ancestral activation promiscuity of ADP-glucose pyrophosphorylases from oxygenic photosynthetic organisms

    Directory of Open Access Journals (Sweden)

    Kuhn Misty L

    2013-02-01

    Full Text Available Abstract Background ADP-glucose pyrophosphorylase (ADP-Glc PPase catalyzes the first committed step in the synthesis of glycogen in bacteria and starch in algae and plants. In oxygenic photosynthetic organisms, ADP-Glc PPase is mainly activated by 3-phosphoglycerate (3-PGA and to a lesser extent by other metabolites. In this work, we analyzed the activation promiscuity of ADP-Glc PPase subunits from the cyanobacterium Anabaena PCC 7120, the green alga Ostreococcus tauri, and potato (Solanum tuberosum tuber by comparing a specificity constant for 3-PGA, fructose-1,6-bisphosphate (FBP, fructose-6-phosphate, and glucose-6-phosphate. Results The 3-PGA specificity constant for the enzymes from Anabaena (homotetramer, O. tauri, and potato tuber was considerably higher than for other activators. O. tauri and potato tuber enzymes were heterotetramers comprising homologous small and large subunits. Conversely, the O. tauri small subunit (OtaS homotetramer was more promiscuous because its FBP specificity constant was similar to that for 3-PGA. To explore the role of both OtaS and OtaL (O. tauri large subunit in determining the specificity of the heterotetramer, we knocked out the catalytic activity of each subunit individually by site-directed mutagenesis. Interestingly, the mutants OtaSD148A/OtaL and OtaS/OtaLD171A had higher specificity constants for 3-PGA than for FBP. Conclusions After gene duplication, OtaS seemed to have lost specificity for 3-PGA compared to FBP. This was physiologically and evolutionarily feasible because co-expression of both subunits restored the specificity for 3-PGA of the resulting heterotetrameric wild type enzyme. This widespread promiscuity seems to be ancestral and intrinsic to the enzyme family. Its presence could constitute an efficient evolutionary mechanism to accommodate the ADP-Glc PPase regulation to different metabolic needs.

  6. Toxic and nontoxic components of botulinum neurotoxin complex are evolved from a common ancestral zinc protein

    Energy Technology Data Exchange (ETDEWEB)

    Inui, Ken [Department of Food and Cosmetic Science, Faculty of Bioindustry, Tokyo University of Agriculture, 196 Yasaka, Abashiri 099-2493 (Japan); Japan Society for the Promotion of Science, 1-8 Chiyoda-ku, Tokyo 102-8472 (Japan); Sagane, Yoshimasa [Department of Food and Cosmetic Science, Faculty of Bioindustry, Tokyo University of Agriculture, 196 Yasaka, Abashiri 099-2493 (Japan); Miyata, Keita [Department of Food and Cosmetic Science, Faculty of Bioindustry, Tokyo University of Agriculture, 196 Yasaka, Abashiri 099-2493 (Japan); Japan Society for the Promotion of Science, 1-8 Chiyoda-ku, Tokyo 102-8472 (Japan); Miyashita, Shin-Ichiro [Department of Food and Cosmetic Science, Faculty of Bioindustry, Tokyo University of Agriculture, 196 Yasaka, Abashiri 099-2493 (Japan); Suzuki, Tomonori [Department of Bacteriology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558 (Japan); Shikamori, Yasuyuki [Agilent Technologies International Japan, Ltd. Takaura-cho 9-1, Hachioji-shi, Tokyo 192-0033 (Japan); Ohyama, Tohru; Niwa, Koichi [Department of Food and Cosmetic Science, Faculty of Bioindustry, Tokyo University of Agriculture, 196 Yasaka, Abashiri 099-2493 (Japan); Watanabe, Toshihiro, E-mail: t-watana@bioindustry.nodai.ac.jp [Department of Food and Cosmetic Science, Faculty of Bioindustry, Tokyo University of Agriculture, 196 Yasaka, Abashiri 099-2493 (Japan)

    2012-03-16

    Highlights: Black-Right-Pointing-Pointer BoNT and NTNHA proteins share a similar protein architecture. Black-Right-Pointing-Pointer NTNHA and BoNT were both identified as zinc-binding proteins. Black-Right-Pointing-Pointer NTNHA does not have a classical HEXXH zinc-coordinating motif similar to that found in all serotypes of BoNT. Black-Right-Pointing-Pointer Homology modeling implied probable key residues involved in zinc coordination. -- Abstract: Zinc atoms play an essential role in a number of enzymes. Botulinum neurotoxin (BoNT), the most potent toxin known in nature, is a zinc-dependent endopeptidase. Here we identify the nontoxic nonhemagglutinin (NTNHA), one of the BoNT-complex constituents, as a zinc-binding protein, along with BoNT. A protein structure classification database search indicated that BoNT and NTNHA share a similar domain architecture, comprising a zinc-dependent metalloproteinase-like, BoNT coiled-coil motif and concanavalin A-like domains. Inductively coupled plasma-mass spectrometry analysis demonstrated that every single NTNHA molecule contains a single zinc atom. This is the first demonstration of a zinc atom in this protein, as far as we know. However, the NTNHA molecule does not possess any known zinc-coordinating motif, whereas all BoNT serotypes possess the classical HEXXH motif. Homology modeling of the NTNHA structure implied that a consensus K-C-L-I-K-X{sub 35}-D sequence common among all NTNHA serotype molecules appears to coordinate a single zinc atom. These findings lead us to propose that NTNHA and BoNT may have evolved distinct functional specializations following their branching out from a common ancestral zinc protein.

  7. Toxic and nontoxic components of botulinum neurotoxin complex are evolved from a common ancestral zinc protein

    International Nuclear Information System (INIS)

    Highlights: ► BoNT and NTNHA proteins share a similar protein architecture. ► NTNHA and BoNT were both identified as zinc-binding proteins. ► NTNHA does not have a classical HEXXH zinc-coordinating motif similar to that found in all serotypes of BoNT. ► Homology modeling implied probable key residues involved in zinc coordination. -- Abstract: Zinc atoms play an essential role in a number of enzymes. Botulinum neurotoxin (BoNT), the most potent toxin known in nature, is a zinc-dependent endopeptidase. Here we identify the nontoxic nonhemagglutinin (NTNHA), one of the BoNT-complex constituents, as a zinc-binding protein, along with BoNT. A protein structure classification database search indicated that BoNT and NTNHA share a similar domain architecture, comprising a zinc-dependent metalloproteinase-like, BoNT coiled-coil motif and concanavalin A-like domains. Inductively coupled plasma-mass spectrometry analysis demonstrated that every single NTNHA molecule contains a single zinc atom. This is the first demonstration of a zinc atom in this protein, as far as we know. However, the NTNHA molecule does not possess any known zinc-coordinating motif, whereas all BoNT serotypes possess the classical HEXXH motif. Homology modeling of the NTNHA structure implied that a consensus K-C-L-I-K-X35-D sequence common among all NTNHA serotype molecules appears to coordinate a single zinc atom. These findings lead us to propose that NTNHA and BoNT may have evolved distinct functional specializations following their branching out from a common ancestral zinc protein.

  8. Paraphyly of organelle DNAs in Cycas Sect. Asiorientales due to ancient ancestral polymorphisms

    Directory of Open Access Journals (Sweden)

    Hsu Tsai-Wen

    2009-07-01

    Full Text Available Abstract Background This study addresses the apportionment of genetic diversity between Cycas revoluta and C. taitungensis, species that constitute the section Asiorientales and represent a unique, basal lineage of the Laurasian genus Cycas. Fossil evidence indicates divergence of the section from the rest of Cycas at least 30 million years ago. Geographically, C. taitungensis is limited to Taiwan whereas C. revoluta is found in the Ryukyu Archipelago and on mainland China. Results The phylogenies of ribosomal ITS region of mtDNA and the intergenic spacer between atpB and rbcL genes of cpDNA were reconstructed. Phylogenetic analyses revealed paraphyly of both loci in the two species and also in the section Asiorientales. The lack of reciprocal monophyly between these long isolated sections is likely due to persistent shared ancestral polymorphisms. Molecular dating estimated that mt- and cp DNA lineages coalesced to the most recent common ancestors (TMRCA about 327 (mt and 204 MYA (cp, corresponding with the divergence of cycad sections in the Mesozoic. Conclusion Fates of newly derived mutations of cycads follow Klopfstein et al.'s surfing model where the majority of new mutations do not spread geographically and remain at low frequencies or are eventually lost by genetic drift. Only successful 'surfing mutations' reach very high frequencies and occupy a large portion of a species range. These mutations exist as dominant cytotypes across populations and species. Geographical subdivision is lacking in both species, even though recurrent gene flow by both pollen and seed is severely limited. In total, the contrasting levels between historical and ongoing gene flow, large population sizes, a long lifespan, and slow mutation rates in both organelle DNAs have all likely contributed to the unusually long duration of paraphyly in cycads.

  9. High-throughput sequencing of three Lemnoideae (duckweeds chloroplast genomes from total DNA.

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    Wenqin Wang

    Full Text Available BACKGROUND: Chloroplast genomes provide a wealth of information for evolutionary and population genetic studies. Chloroplasts play a particularly important role in the adaption for aquatic plants because they float on water and their major surface is exposed continuously to sunlight. The subfamily of Lemnoideae represents such a collection of aquatic species that because of photosynthesis represents one of the fastest growing plant species on earth. METHODS: We sequenced the chloroplast genomes from three different genera of Lemnoideae, Spirodela polyrhiza, Wolffiella lingulata and Wolffia australiana by high-throughput DNA sequencing of genomic DNA using the SOLiD platform. Unfractionated total DNA contains high copies of plastid DNA so that sequences from the nucleus and mitochondria can easily be filtered computationally. Remaining sequence reads were assembled into contiguous sequences (contigs using SOLiD software tools. Contigs were mapped to a reference genome of Lemna minor and gaps, selected by PCR, were sequenced on the ABI3730xl platform. CONCLUSIONS: This combinatorial approach yielded whole genomic contiguous sequences in a cost-effective manner. Over 1,000-time coverage of chloroplast from total DNA were reached by the SOLiD platform in a single spot on a quadrant slide without purification. Comparative analysis indicated that the chloroplast genome was conserved in gene number and organization with respect to the reference genome of L. minor. However, higher nucleotide substitution, abundant deletions and insertions occurred in non-coding regions of these genomes, indicating a greater genomic dynamics than expected from the comparison of other related species in the Pooideae. Noticeably, there was no transition bias over transversion in Lemnoideae. The data should have immediate applications in evolutionary biology and plant taxonomy with increased resolution and statistical power.

  10. A Common Ancestral Mutation in CRYBB3 Identified in Multiple Consanguineous Families with Congenital Cataracts

    Science.gov (United States)

    Irum, Bushra; Khan, Arif O.; Wang, Qiwei; Li, David; Khan, Asma A.; Husnain, Tayyab; Akram, Javed; Riazuddin, Sheikh

    2016-01-01

    development. Conclusion Here, we report a common ancestral mutation in CRYBB3 associated with autosomal recessive congenital cataracts identified in four familial cases of Pakistani origin. PMID:27326458

  11. Effects of interleukin-10 on cutaneous wounds and scars in humans of African continental ancestral origin.

    Science.gov (United States)

    Kieran, Ingrid; Taylor, Catherine; Bush, Jim; Rance, Mark; So, Karen; Boanas, Adam; Metcalfe, Anthony; Hobson, Rosalind; Goldspink, Nick; Hutchison, John; Ferguson, Mark

    2014-01-01

    Scars in humans of African continental ancestry heal with an exaggerated inflammatory response and a generally wider scar. Interleukin-10 is an anti-inflammatory and antifibrotic cytokine. A randomized controlled trial in Caucasians found that exogenous interleukin-10 resulted in improved macroscopic scar appearance and reduced scar redness. We investigated the effects of interleukin-10 on cutaneous scarring in volunteers of African ancestral origin in an exploratory, single-center, within-subject, double-blind randomized controlled trial. Fifty-six subjects received two of four potential prerandomized concentrations of interleukin-10 (5, 25, 100, and 250 ng/100 µL) in two full-thickness incisions on the upper inner arms. Anatomically matching incisions on the contralateral arm were treated with placebo. Scars were excised at 1 month for histological analysis and were redosed with the same regimen. Resultant excision scars were followed up for 12 months for scar width measurement and scoring. Scoring was performed by trial doctors, subjects, and a panel. Incisions treated with 100 ng/100 µL interleukin-10 had significantly reduced microscopic scar widths. Incisions treated with 5 and 25 ng/100 µL interleukin-10 were also narrower, but not significantly. There were no differences observed in pro-inflammatory or pro-fibrotic markers between interleukin-10 and placebo treatment. There was no long-term evidence that 100 ng/100 µL interleukin-10 had a therapeutic effect on macroscopic scar width or appearance, as excisions treated with this concentration were significantly wider than placebo between 8 and 12 months of maturation. Doctors showed a trend toward favoring the macroscopic appearance of placebo-treated excisions compared with those treated with 250 ng/100 µL interleukin-10. Panelists scored placebo-treated excisions as significantly better-appearing than those treated with 250 ng/100 µL interleukin-10. Doctors' scores showed a

  12. Chloroplast phylogenomic data from the green algal order Sphaeropleales (Chlorophyceae, Chlorophyta) reveal complex patterns of sequence evolution.

    Science.gov (United States)

    Fučíková, Karolina; Lewis, Paul O; Lewis, Louise A

    2016-05-01

    Chloroplast sequence data are widely used to infer phylogenies of plants and algae. With the increasing availability of complete chloroplast genome sequences, the opportunity arises to resolve ancient divergences that were heretofore problematic. On the flip side, properly analyzing large multi-gene data sets can be a major challenge, as these data may be riddled with systematic biases and conflicting signals. Our study contributes new data from nine complete and four fragmentary chloroplast genome sequences across the green algal order Sphaeropleales. Our phylogenetic analyses of a 56-gene data set show that analyzing these data on a nucleotide level yields a well-supported phylogeny - yet one that is quite different from a corresponding amino acid analysis. We offer some possible explanations for this conflict through a range of analyses of modified data sets. In addition, we characterize the newly sequenced genomes in terms of their structure and content, thereby further contributing to the knowledge of chloroplast genome evolution. PMID:26903036

  13. Ozone-induced changes in the chloroplast structure of conifer needles, and their use in ozone diagnostics

    International Nuclear Information System (INIS)

    Ozone induces characteristic symptoms in the chloroplasts of the needles of several coniferous species. Chloroplasts are (1) reduced in size and (2) the stroma is electron dense. Moreover (3) these chloroplast alterations are more pronounced in the outer mesophyll cell layers and in the upper side of the needle compared to the inner layers and lower side. The syndrome, including the three symptoms (1)-(3), is found in the green needles of Scots pine and Norway spruce not only in the experimental fumigations, but also in mature trees in the field, and has potential for diagnosis of ozone stress. For sound ozone diagnostics all three symptoms must be present in the samples studied. The symptoms in relation to needle anatomy and physiology is discussed, and recommendations for sampling and analysis are given. - Ozone-induced alterations in chloroplast structure of conifer needles are reviewed, and recommendations for field monitoring given

  14. Spatial location of photosystem pigment-protein complexes in thylakoid membranes of chloroplasts of Pisun sativum studied by chlorophyll fluorescence

    Czech Academy of Sciences Publication Activity Database

    Vácha, František; Adamec, František; Valenta, J.; Vácha, M.

    122-123, Spec.iss. (2007), s. 301-303. ISSN 0022-2313 Institutional research plan: CEZ:AV0Z50510513 Keywords : chloroplasts * Pisum sativum Subject RIV: BO - Biophysics Impact factor: 1.611, year: 2007

  15. A Comparison of the First Two Sequenced Chloroplast Genomes in Asteraceae: Lettuce and Sunflower

    Energy Technology Data Exchange (ETDEWEB)

    Timme, Ruth E.; Kuehl, Jennifer V.; Boore, Jeffrey L.; Jansen, Robert K.

    2006-01-20

    Asteraceae is the second largest family of plants, with over 20,000 species. For the past few decades, numerous phylogenetic studies have contributed to our understanding of the evolutionary relationships within this family, including comparisons of the fast evolving chloroplast gene, ndhF, rbcL, as well as non-coding DNA from the trnL intron plus the trnLtrnF intergenic spacer, matK, and, with lesser resolution, psbA-trnH. This culminated in a study by Panero and Funk in 2002 that used over 13,000 bp per taxon for the largest taxonomic revision of Asteraceae in over a hundred years. Still, some uncertainties remain, and it would be very useful to have more information on the relative rates of sequence evolution among various genes and on genome structure as a potential set of phylogenetic characters to help guide future phylogenetic structures. By way of contributing to this, we report the first two complete chloroplast genome sequences from members of the Asteraceae, those of Helianthus annuus and Lactuca sativa. These plants belong to two distantly related subfamilies, Asteroideae and Cichorioideae, respectively. In addition to these, there is only one other published chloroplast genome sequence for any plant within the larger group called Eusterids II, that of Panax ginseng (Araliaceae, 156,318 bps, AY582139). Early chloroplast genome mapping studies demonstrated that H. annuus and L. sativa share a 22 kb inversion relative to members of the subfamily Barnadesioideae. By comparison to outgroups, this inversion was shown to be derived, indicating that the Asteroideae and Cichorioideae are more closely related than either is to the Barnadesioideae. Later sequencing study found that taxa that share this 22 kb inversion also contain within this region a second, smaller, 3.3 kb inversion. These sequences also enable an analysis of patterns of shared repeats in the genomes at fine level and of RNA editing by comparison to available EST sequences. In addition, since

  16. Expression of ROS-responsive genes and transcription factors after metabolic formation of H2O2 in chloroplasts

    OpenAIRE

    Balazadeh, Salma; Jaspert, Nils; Arif, Muhammad; Mueller-Roeber, Bernd; Maurino, Veronica G.

    2012-01-01

    Glycolate oxidase (GO) catalyses the oxidation of glycolate to glyoxylate, thereby consuming O(2) and producing H(2)O(2). In this work, Arabidopsis thaliana plants expressing GO in the chloroplasts (GO plants) were used to assess the expressional behavior of reactive oxygen species (ROS)-responsive genes and transcription factors (TFs) after metabolic induction of H(2)O(2) formation in chloroplasts. In this organelle, GO uses the glycolate derived from the oxygenase activity of RubisCO. Here,...

  17. Comparative chloroplast genomics and phylogenetics of Fagopyrum esculentum ssp. ancestrale – A wild ancestor of cultivated buckwheat

    Directory of Open Access Journals (Sweden)

    Dhingra Amit

    2008-05-01

    Full Text Available Abstract Background Chloroplast genome sequences are extremely informative about species-interrelationships owing to its non-meiotic and often uniparental inheritance over generations. The subject of our study, Fagopyrum esculentum, is a member of the family Polygonaceae belonging to the order Caryophyllales. An uncertainty remains regarding the affinity of Caryophyllales and the asterids that could be due to undersampling of the taxa. With that background, having access to the complete chloroplast genome sequence for Fagopyrum becomes quite pertinent. Results We report the complete chloroplast genome sequence of a wild ancestor of cultivated buckwheat, Fagopyrum esculentum ssp. ancestrale. The sequence was rapidly determined using a previously described approach that utilized a PCR-based method and employed universal primers, designed on the scaffold of multiple sequence alignment of chloroplast genomes. The gene content and order in buckwheat chloroplast genome is similar to Spinacia oleracea. However, some unique structural differences exist: the presence of an intron in the rpl2 gene, a frameshift mutation in the rpl23 gene and extension of the inverted repeat region to include the ycf1 gene. Phylogenetic analysis of 61 protein-coding gene sequences from 44 complete plastid genomes provided strong support for the sister relationships of Caryophyllales (including Polygonaceae to asterids. Further, our analysis also provided support for Amborella as sister to all other angiosperms, but interestingly, in the bayesian phylogeny inference based on first two codon positions Amborella united with Nymphaeales. Conclusion Comparative genomics analyses revealed that the Fagopyrum chloroplast genome harbors the characteristic gene content and organization as has been described for several other chloroplast genomes. However, it has some unique structural features distinct from previously reported complete chloroplast genome sequences. Phylogenetic

  18. Production of therapeutic proteins in algae, analysis of expression of seven human proteins in the chloroplast of Chlamydomonas reinhardtii

    OpenAIRE

    Rasala, Beth A.; Muto, Machiko; Lee, Philip A.; Jager, Michal; Cardoso, Rosa MF; Behnke, Craig A; Kirk, Peter; Hokanson, Craig A.; Crea, Roberto; Mendez, Michael; Mayfield, Stephen P

    2010-01-01

    Recombinant proteins are widely used today in many industries, including the biopharmaceutical industry, and can be expressed in bacteria, yeasts, mammalian and insect cell cultures, or in transgenic plants and animals. In addition, transgenic algae have also been shown to support recombinant protein expression, both from the nuclear and chloroplast genomes. However, to date, there are only a few reports on recombinant proteins expressed in the algal chloroplast. It is unclear if this is due ...

  19. Chloroplast genes are expressed during intracellular symbiotic association of Vaucheria litorea plastids with the sea slug Elysia chlorotica.

    OpenAIRE

    Mujer, C V; Andrews, D L; Manhart, J R; Pierce, S K; Rumpho, M E

    1996-01-01

    The marine slug Elysia chlorotica (Gould) forms an intracellular symbiosis with photosynthetically active chloroplasts from the chromophytic alga Vaucheria litorea (C. Agardh). This symbiotic association was characterized over a period of 8 months during which E. chlorotica was deprived of V. litorea but provided with light and CO2. The fine structure of the symbiotic chloroplasts remained intact in E. chlorotica even after 8 months of starvation as revealed by electron microscopy. Southern b...

  20. La modernidad, el cuidado de la salud y la cultura ancestral.

    Directory of Open Access Journals (Sweden)

    Ana Cecilia Becerra

    2009-11-01

    Full Text Available La modernidad es tanto un período histórico como un concepto filosófico y sociológico que impuso la razón y el método formal sobre todos los actos políticos, sociales y epistemológicos de las distintas culturas del mundo. La modernidad se construyó en su momento sobre el imaginario de la superioridad europea1 y durante el período colonial fue la causante del proceso avasallador de exterminio y de desconocimiento de las sociedades y culturas indígenas de América. Ella, con sus valores patriarcales y formales, desplazó la ética del cuidado y del abrigo de los pueblos autóctonos imponiendo una lógica racional, calculadora e impersonal. Al desconocer y casi negar en su totalidad la cosmovisión ancestral de curar y cuidar, relegó los ejercicios profesionalizantes de la salud bajo el amparo de la mercantilización del capitalismo mundial integrado. La modernidad, desde el inicio y en la actualidad, ha impregnado la cultura de todos los pueblos y ha condicionado todos los actos académicos en las instituciones escolares y universitarias. La perpetuación de un modelo positivista y occidentalizado ha sido una constante en las aulas universitarias y en las disciplinas, sobre todo en las ciencias de la salud. Históricamente el conocimiento en salud ha sido construido con base en el enfoque positivista y la concepción biologista del proceso salud-enfermedad, lo cual lleva a una fragmentación del saber, disyunción del sujeto y el objeto en la producción del conocimiento, y a una incapacidad de asumir al ser humano en todas sus dimensiones, razón de ser de la acción en salud, como totalidad y unidad integral2. Este panorama aquí planteado deja un gran reto epistemológico a los profesionales y a los docentes de las ciencias de la salud en general y de enfermería en particular. Vista la enfermería desde la fundamentación del cuidado de la salud, no se puede descontextualizar ni escindir de nuestra propia cultura, pretendiendo

  1. La modernidad, el cuidado de la salud y la cultura ancestral

    Directory of Open Access Journals (Sweden)

    Ana Cecilia Becerra

    2008-09-01

    Full Text Available La modernidad es tanto un período histórico como un concepto filosófico y sociológico que impuso la razón y el método formal sobre todos los actos políticos, sociales y epistemológicos de las distintas culturas del mundo. La modernidad se construyó en su momento sobre el imaginario de la superioridad europea1 y durante el período colonial fue la causante del proceso avasallador de exterminio y de desconocimiento de las sociedades y culturas indígenas de América.Ella, con sus valores patriarcales y formales, desplazó la ética del cuidado y del abrigo de los pueblos autóctonos imponiendo una lógica racional, calculadora e impersonal. Al desconocer y casi negar en su totalidad la cosmovisión ancestral de curar y cuidar, relegó los ejercicios profesionalizantes de la salud bajo el amparo de la mercantilización del capitalismo mundial integrado.La modernidad, desde el inicio y en la actualidad, ha impregnado la cultura de todos los pueblos y ha condicionado todos los actos académicos en las instituciones escolares y universitarias. La perpetuación de un modelo positivista y occidentalizado ha sido una constante en las aulas universitarias y en las disciplinas, sobre todo en las ciencias de la salud. Históricamente el conocimiento en salud ha sido construido con base en el enfoque positivista y la concepción biologista del proceso salud-enfermedad, lo cual lleva a una fragmentación del saber, disyunción del sujeto y el objeto en la producción del conocimiento, y a una incapacidad de asumir al ser humano en todas sus dimensiones, razón de ser de la acción en salud, como totalidad y unidad integral2.Este panorama aquí planteado deja un gran reto epistemológico a los profesionales y a los docentes de las ciencias de la salud en general y de enfermería en particular. Vista la enfermería desde la fundamentación del cuidado de la salud, no se puede descontextualizar ni escindir de nuestra propia cultura, pretendiendo

  2. Kinetic modeling and exploratory numerical simulation of chloroplastic starch degradation

    Directory of Open Access Journals (Sweden)

    Nag Ambarish

    2011-06-01

    Full Text Available Abstract Background Higher plants and algae are able to fix atmospheric carbon dioxide through photosynthesis and store this fixed carbon in large quantities as starch, which can be hydrolyzed into sugars serving as feedstock for fermentation to biofuels and precursors. Rational engineering of carbon flow in plant cells requires a greater understanding of how starch breakdown fluxes respond to variations in enzyme concentrations, kinetic parameters, and metabolite concentrations. We have therefore developed and simulated a detailed kinetic ordinary differential equation model of the degradation pathways for starch synthesized in plants and green algae, which to our knowledge is the most complete such model reported to date. Results Simulation with 9 internal metabolites and 8 external metabolites, the concentrations of the latter fixed at reasonable biochemical values, leads to a single reference solution showing β-amylase activity to be the rate-limiting step in carbon flow from starch degradation. Additionally, the response coefficients for stromal glucose to the glucose transporter kcat and KM are substantial, whereas those for cytosolic glucose are not, consistent with a kinetic bottleneck due to transport. Response coefficient norms show stromal maltopentaose and cytosolic glucosylated arabinogalactan to be the most and least globally sensitive metabolites, respectively, and β-amylase kcat and KM for starch to be the kinetic parameters with the largest aggregate effect on metabolite concentrations as a whole. The latter kinetic parameters, together with those for glucose transport, have the greatest effect on stromal glucose, which is a precursor for biofuel synthetic pathways. Exploration of the steady-state solution space with respect to concentrations of 6 external metabolites and 8 dynamic metabolite concentrations show that stromal metabolism is strongly coupled to starch levels, and that transport between compartments serves to

  3. The reduced state of the plastoquinone pool is required for chloroplast-mediated stomatal closure in response to calcium stimulation.

    Science.gov (United States)

    Wang, Wen-Hua; He, En-Ming; Chen, Juan; Guo, Ying; Chen, Juan; Liu, Xiang; Zheng, Hai-Lei

    2016-04-01

    Besides their participation in photosynthesis, leaf chloroplasts function in plant responses to stimuli, yet how they direct stimulus-induced stomatal movement remains elusive. Here, we showed that over-reduction of the plastoquinone (PQ) pool by dibromothymoquinone (DBMIB) was closely associated with stomatal closure in plants which required chloroplastic H2 O2 generation in the mesophyll. External application of H2 O2 reduced the PQ pool, whereas the cell-permeable reactive oxygen species (ROS) scavenger N-acetylcysteine (NAC) reversed the DBMIB-induced over-reduction of the PQ pool and stomatal closure. Mesophyll chloroplasts are key players of extracellular Ca(2+) (Ca(2+) o )-induced stomatal closure, but when treated with either 3-(3',4'-dichlorophenyl)-1,1-dimethylurea (DCMU) or NAC they failed to facilitate Ca(2+) o -induced stomatal closure due to the inhibition of chloroplastic H2 O2 synthesis in mesophyll. Similarly, the Arabidopsis electron transfer chain-related mutants npq4-1, stn7 and cas-1 exhibited diverse responses to Ca(2+) o or DBMIB. Transcriptome analysis also demonstrated that the PQ pool signaling pathway shared common responsive genes with the H2 O2 signaling pathway. These results implicated a mechanism for chloroplast-mediated stomatal closure involving the generation of mesophyll chloroplastic H2 O2 based on the reduced state of the PQ pool, which is calcium-sensing receptor (CAS) and LHCII phosphorylation dependent. PMID:26945669

  4. The complete chloroplast genome of Gracilariopsis lemaneiformis (Rhodophyta) gives new insight into the evolution of family Gracilariaceae.

    Science.gov (United States)

    Du, Qingwei; Bi, Guiqi; Mao, Yunxiang; Sui, Zhenghong

    2016-06-01

    The complete chloroplast genome of Gracilariopsis lemaneiformis was recovered from a Next Generation Sequencing data set. Without quadripartite structure, this chloroplast genome (183,013 bp, 27.40% GC content) contains 202 protein-coding genes, 34 tRNA genes, 3 rRNA genes, and 1 tmRNA gene. Synteny analysis showed plasmid incorporation regions in chloroplast genomes of three species of family Gracilariaceae and in Grateloupia taiwanensis of family Halymeniaceae. Combined with reported red algal plasmid sequences in nuclear and mitochondrial genomes, we postulated that red algal plasmids may have played an important role in ancient horizontal gene transfer among nuclear, chloroplast, and mitochondrial genomes. Substitution rate analysis showed that purifying selective forces maintaining stability of protein-coding genes of nine red algal chloroplast genomes over long periods must be strong and that the forces acting on gene groups and single genes of nine red algal chloroplast genomes were similar and consistent. The divergence of Gp. lemaneiformis occurred ~447.98 million years ago (Mya), close to the divergence time of genus Pyropia and Porphyra (443.62 Mya). PMID:27273536

  5. Kinetics of /sup 14/C distribution during photosynthesis by chloroplast preparations isolated from the siphonous alga Caulerpa simpliciuscula

    Energy Technology Data Exchange (ETDEWEB)

    Grant, B.R.; Howard, R.J.

    1980-07-01

    The kinetics of /sup 14/C-labeling of compounds produced during photosynthesis by chloroplast preparations isolated from the green alga Caulerpa simpliciuscula were studied. After 10 minutes photosynthesis sucrose contained more /sup 14/C than any other product, and continued to accumulate radioactivity during the whole hour of incubation. Glucose-6-phosphate and alanine also behaved as end products and continued to accumulate label during the period. In these organelles, glucose-6-phosphate replaced triose phosphate as the main compound exported from the chloroplast during shorter periods of photosynthesis. When either glucose-6-phosphate or 3-phosphoglycerate was supplied to the isolated chloroplasts, they were metabolized, but were not converted to either sucrose or alanine. It is proposed that many of the differences in metabolism which distinguish these algal chloroplasts from those isolated from higher plants are due to their isolation in the form of cytoplasts, i.e., chloroplasts surrounded by a thin layer of extrachloroplastic material which is membrane-bound. The restriction of diffusion of intermediates from the chloroplast by this cytoplast membrane appears to be at least as important as the rather small amount of cytoplasm present in determining the properties observed.

  6. Kinetics of 14C distribution during photosynthesis by chloroplast preparations isolated from the siphonous alga Caulerpa simpliciuscula

    International Nuclear Information System (INIS)

    The kinetics of 14C-labeling of compounds produced during photosynthesis by chloroplast preparations isolated from the green alga Caulerpa simpliciuscula were studied. After 10 minutes photosynthesis sucrose contained more 14C than any other product, and continued to accumulate radioactivity during the whole hour of incubation. Glucose-6-phosphate and alanine also behaved as end products and continued to accumulate label during the period. In these organelles, glucose-6-phosphate replaced triose phosphate as the main compound exported from the chloroplast during shorter periods of photosynthesis. When either glucose-6-phosphate or 3-phosphoglycerate was supplied to the isolated chloroplasts, they were metabolized, but were not converted to either sucrose or alanine. It is proposed that many of the differences in metabolism which distinguish these algal chloroplasts from those isolated from higher plants are due to their isolation in the form of cytoplasts, i.e., chloroplasts surrounded by a thin layer of extrachloroplastic material which is membrane-bound. The restriction of diffusion of intermediates from the chloroplast by this cytoplast membrane appears to be at least as important as the rather small amount of cytoplasm present in determining the properties observed

  7. Digestive system of the sacoglossan Plakobranchus ocellatus (Gastropoda: Opisthobranchia): light- and electron-microscopic observations with remarks on chloroplast retention.

    Science.gov (United States)

    Hirose, Euichi

    2005-08-01

    The sacoglossan Plakobranchus ocellatus feeds by sucking the cytoplasmic contents from algae and retains intact algal chloroplasts within the cells of the digestive gland. Morphology of the entire digestive system of this species was firstly described by means of a combination of histology and electron microscopy (both SEM and TEM). The short alimentary canal is confined to the head, and the anus opens at the anterior right corner of the pericardial swelling, as is the case in many non-shelled sacoglossans. The alimentary canal of the specimens examined rarely contained ingesta, suggesting that the retained chloroplasts provide sufficient nourishment to the sacoglossan hosts and that sea slugs with empty stomachs survive well in the field. The digestive gland, with the retained chloroplasts, branches from the stomach and is sparsely distributed throughout the body, including the head region, but is aggregated mainly in the dorsal lamellae. Chloroplasts were occasionally found in the epithelial cells in the transitional region from the stomach wall to the digestive gland, which may be a site at which chloroplasts are incorporated into the animal cells by endocytosis. Numerous microvilli filling the lumen of the digestive gland suggest that molecules are actively transferred within the gland. The sea slug thus apparently provides a favorable environment to support the long-term retention and function of chloroplasts. PMID:16141704

  8. Estimation of hominoid ancestral population sizes under bayesian coalescent models incorporating mutation rate variation and sequencing errors.

    Science.gov (United States)

    Burgess, Ralph; Yang, Ziheng

    2008-09-01

    Estimation of population parameters for the common ancestors of humans and the great apes is important in understanding our evolutionary history. In particular, inference of population size for the human-chimpanzee common ancestor may shed light on the process by which the 2 species separated and on whether the human population experienced a severe size reduction in its early evolutionary history. In this study, the Bayesian method of ancestral inference of Rannala and Yang (2003. Bayes estimation of species divergence times and ancestral population sizes using DNA sequences from multiple loci. Genetics. 164:1645-1656) was extended to accommodate variable mutation rates among loci and random species-specific sequencing errors. The model was applied to analyze a genome-wide data set of approximately 15,000 neutral loci (7.4 Mb) aligned for human, chimpanzee, gorilla, orangutan, and macaque. We obtained robust and precise estimates for effective population sizes along the hominoid lineage extending back approximately 30 Myr to the cercopithecoid divergence. The results showed that ancestral populations were 5-10 times larger than modern humans along the entire hominoid lineage. The estimates were robust to the priors used and to model assumptions about recombination. The unusually low X chromosome divergence between human and chimpanzee could not be explained by variation in the male mutation bias or by current models of hybridization and introgression. Instead, our parameter estimates were consistent with a simple instantaneous process for human-chimpanzee speciation but showed a major reduction in X chromosome effective population size peculiar to the human-chimpanzee common ancestor, possibly due to selective sweeps on the X prior to separation of the 2 species. PMID:18603620

  9. Saccharomyces cerevisiae Bat1 and Bat2 aminotransferases have functionally diverged from the ancestral-like Kluyveromyces lactis orthologous enzyme.

    Directory of Open Access Journals (Sweden)

    Maritrini Colón

    Full Text Available BACKGROUND: Gene duplication is a key evolutionary mechanism providing material for the generation of genes with new or modified functions. The fate of duplicated gene copies has been amply discussed and several models have been put forward to account for duplicate conservation. The specialization model considers that duplication of a bifunctional ancestral gene could result in the preservation of both copies through subfunctionalization, resulting in the distribution of the two ancestral functions between the gene duplicates. Here we investigate whether the presumed bifunctional character displayed by the single branched chain amino acid aminotransferase present in K. lactis has been distributed in the two paralogous genes present in S. cerevisiae, and whether this conservation has impacted S. cerevisiae metabolism. PRINCIPAL FINDINGS: Our results show that the KlBat1 orthologous BCAT is a bifunctional enzyme, which participates in the biosynthesis and catabolism of branched chain aminoacids (BCAAs. This dual role has been distributed in S. cerevisiae Bat1 and Bat2 paralogous proteins, supporting the specialization model posed to explain the evolution of gene duplications. BAT1 is highly expressed under biosynthetic conditions, while BAT2 expression is highest under catabolic conditions. Bat1 and Bat2 differential relocalization has favored their physiological function, since biosynthetic precursors are generated in the mitochondria (Bat1, while catabolic substrates are accumulated in the cytosol (Bat2. Under respiratory conditions, in the presence of ammonium and BCAAs the bat1Δ bat2Δ double mutant shows impaired growth, indicating that Bat1 and Bat2 could play redundant roles. In K. lactis wild type growth is independent of BCAA degradation, since a Klbat1Δ mutant grows under this condition. CONCLUSIONS: Our study shows that BAT1 and BAT2 differential expression and subcellular relocalization has resulted in the distribution of the

  10. Extensive Chromosomal Reorganization in the Evolution of New World Muroid Rodents (Cricetidae, Sigmodontinae): Searching for Ancestral Phylogenetic Traits.

    Science.gov (United States)

    Pereira, Adenilson Leão; Malcher, Stella Miranda; Nagamachi, Cleusa Yoshiko; O'Brien, Patricia Caroline Mary; Ferguson-Smith, Malcolm Andrew; Mendes-Oliveira, Ana Cristina; Pieczarka, Julio Cesar

    2016-01-01

    Sigmodontinae rodents show great diversity and complexity in morphology and ecology. This diversity is accompanied by extensive chromosome variation challenging attempts to reconstruct their ancestral genome. The species Hylaeamys megacephalus--HME (Oryzomyini, 2n = 54), Necromys lasiurus--NLA (Akodontini, 2n = 34) and Akodon sp.--ASP (Akodontini, 2n = 10) have extreme diploid numbers that make it difficult to understand the rearrangements that are responsible for such differences. In this study we analyzed these changes using whole chromosome probes of HME in cross-species painting of NLA and ASP to construct chromosome homology maps that reveal the rearrangements between species. We include data from the literature for other Sigmodontinae previously studied with probes from HME and Mus musculus (MMU) probes. We also use the HME probes on MMU chromosomes for the comparative analysis of NLA with other species already mapped by MMU probes. Our results show that NLA and ASP have highly rearranged karyotypes when compared to HME. Eleven HME syntenic blocks are shared among the species studied here. Four syntenies may be ancestral to Akodontini (HME2/18, 3/25, 18/25 and 4/11/16) and eight to Sigmodontinae (HME26, 1/12, 6/21, 7/9, 5/17, 11/16, 20/13 and 19/14/19). Using MMU data we identified six associations shared among rodents from seven subfamilies, where MMU3/18 and MMU8/13 are phylogenetic signatures of Sigmodontinae. We suggest that the associations MMU2entire, MMU6proximal/12entire, MMU3/18, MMU8/13, MMU1/17, MMU10/17, MMU12/17, MMU5/16, MMU5/6 and MMU7/19 are part of the ancestral Sigmodontinae genome. PMID:26800516

  11. Ancestral polymorphism at the major histocompatibility complex (MHCIIß in the Nesospiza bunting species complex and its sister species (Rowettia goughensis

    Directory of Open Access Journals (Sweden)

    van Rensburg Alexandra

    2012-08-01

    Full Text Available Abstract Background The major histocompatibility complex (MHC is an important component of the vertebrate immune system and is frequently used to characterise adaptive variation in wild populations due to its co-evolution with pathogens. Passerine birds have an exceptionally diverse MHC with multiple gene copies and large numbers of alleles compared to other avian taxa. The Nesospiza bunting species complex (two species on Nightingale Island; one species with three sub-species on Inaccessible Island represents a rapid adaptive radiation at a small, isolated archipelago, and is thus an excellent model for the study of adaptation and speciation. In this first study of MHC in Nesospiza buntings, we aim to characterize MHCIIß variation, determine the strength of selection acting at this gene region and assess the level of shared polymorphism between the Nesospiza species complex and its putative sister taxon, Rowettia goughensis, from Gough Island. Results In total, 23 unique alleles were found in 14 Nesospiza and 2 R. goughensis individuals encoding at least four presumably functional loci and two pseudogenes. There was no evidence of ongoing selection on the peptide binding region (PBR. Of the 23 alleles, 15 were found on both the islands inhabited by Nesospiza species, and seven in both Nesospiza and Rowettia; indications of shared, ancestral polymorphism. A gene tree of Nesospiza MHCIIß alleles with several other passerine birds shows three highly supported Nesospiza-specific groups. All R. goughensis alleles were shared with Nesospiza, and these alleles were found in all three Nesospiza sequence groups in the gene tree, suggesting that most of the observed variation predates their phylogenetic split. Conclusions Lack of evidence of selection on the PBR, together with shared polymorphism across the gene tree, suggests that population variation of MHCIIß among Nesospiza and Rowettia is due to ancestral polymorphism rather than local selective

  12. Thermotolerant Yeast Strains Adapted by Laboratory Evolution Show Trade-Off at Ancestral Temperatures and Preadaptation to Other Stresses

    DEFF Research Database (Denmark)

    Caspeta, Luis; Nielsen, Jens

    2015-01-01

    adaptive laboratory evolution, we previously isolated seven Saccharomyces cerevisiae strains with improved growth at 40°C. Here, we show that genetic adaptations to high temperature caused a growth trade-off at ancestral temperatures, reduced cellular functions, and improved tolerance of other stresses...... proteins showed that the lethal temperature for yeast is around 49°C, as a large fraction of the yeast proteins denature above this temperature. Our analysis also indicated that the number of functions involved in controlling the growth rate decreased in the thermotolerant strains compared with the number...

  13. Coassembly of Photosystem II and ATPase as Artificial Chloroplast for Light-Driven ATP Synthesis.

    Science.gov (United States)

    Feng, Xiyun; Jia, Yi; Cai, Peng; Fei, Jinbo; Li, Junbai

    2016-01-26

    Adenosine triphosphate (ATP) is one of the most important energy sources in living cells, which can drive serial key biochemical processes. However, generation of a proton gradient for ATP production in an artificial way poses a great challenge. In nature, photophosphorylation occurring in chloroplasts is an ideal prototype of ATP production. In this paper we imitate the light-to-ATP conversion process occurring in the thylakoid membrane by construction of FoF1-ATPase proteoliposome-coated PSII-based microspheres with well-defined core@shell structures using molecular assembly. Under light illumination, PSII can split water into protons, oxygen, and electrons and can generate a proton gradient for ATPase to produce ATP. Thus, an artificially designed chloroplast for PSII-driven ATP synthesis is realized. This biomimetic system will help to understand the photophosphorylation process and may facilitate the development of ATP-driven devices by remote light control. PMID:26615669

  14. A chloroplast pathway for the de novo biosynthesis of triacylglycerol in Chlamydomonas reinhardtii

    Energy Technology Data Exchange (ETDEWEB)

    Fan, J.; Xu, C.; Andre, C.

    2011-06-23

    Neutral lipid metabolism has been extensively studied in yeast, plants and mammals. In contrast, little information is available regarding the biochemical pathway, enzymes and regulatory factors involved in the biosynthesis of triacylglycerol (TAG) in microalgae. In the conventional TAG biosynthetic pathway widely accepted for yeast, plants and mammals, TAG is assembled in the endoplasmic reticulum (ER) from its immediate precursor diacylglycerol (DAG) made by ER-specific acyltransferases, and is deposited exclusively in lipid droplets in the cytosol. Here, we demonstrated that the unicellular microalga Chlamydomonas reinhardtii employs a distinct pathway that uses DAG derived almost exclusively from the chloroplast to produce TAG. This unique TAG biosynthesis pathway is largely dependent on de novo fatty acid synthesis, and the TAG formed in this pathway is stored in lipid droplets in both the chloroplast and the cytosol. These findings have wide implications for understanding TAG biosynthesis and storage and other areas of lipid metabolism in microalgae and other organisms.

  15. Simultaneous isolation of intact mitochondria and chloroplasts from a single pulping of plant tissue.

    Science.gov (United States)

    Rödiger, Anja; Baudisch, Bianca; Klösgen, Ralf Bernd

    2010-05-15

    Isolated organelles are suitable tools for the investigation of organelle function. However, if the properties of different organelles are to be compared, analysis is generally impeded by the fact that the organelles are isolated independently from each other from different specimens, different tissues or even different plants, i.e. the organelles have been exposed to different conditions during growth and development. Here we describe a method to isolate intact chloroplasts and mitochondria simultaneously from a single pulping of pea leaves, which results in organelles with an essentially identical physiological background. The functionality of the isolated chloroplasts and mitochondria is demonstrated by protein transport experiments, which yield results identical to those obtained with independently isolated organelles. With slight modifications, the method is also successfully applied to organelles from potato and spinach, which implies that it may be generally applicable to organelles from many different species. PMID:20045215

  16. In vitro induction, isolation and transfer of chloroplast mutations in Nicotiana

    International Nuclear Information System (INIS)

    Protoplast cultures of Nicotiana plumbaginifolia have been used for the isolation of mutants resistant to antibiotics and to photosynthesis-inhibiting herbicides. The effectiveness of N-ethyl-N-nitrosourea in inducing different chloroplast mutations, establishing proper selective conditions in cell cultures, plant regeneration from resistant cell lines and inheritance of these markers are presented. Bacterial protein-synthesis inhibitors (streptomycin and lincomycin) were used in the selection of a large number of chloroplast mutants under standard culture conditions, while special 'photomixotrophic' culture conditions, for selecting mutants resistant to photosynthesis-inhibiting herbicides, had to be established. Under these culture conditions, the primary symptom of photosynthetic electron-transport inhibition by herbicides (bleaching) can be observed and selection for resistance can be carried out. Protoplast fusion has been shown to be suitable for the 'rescue' of mutant plastids from an undesirable nuclear background, from transfer into a different background, or even transfer into a completely different species. (author)

  17. Effects of slow clinorotation on lipid contents and proton permeability of thylakoid membranes of pea chloroplasts

    Science.gov (United States)

    Mikhaylenko, N. F.; Sytnik, S. K.; Zolotareva, E. K.

    Photochemical characteristics and lipid composition of thylakoid membranes from 12 day-old pea leaves that were exposed to slow clino-rotation were examined and compared with a vertical control. Proton permeability of thylakoid membranes was estimated from light-induced proton uptake (ΔH+) and post-illumination proton efflux in chloroplast suspensions. The ΔpH magnitude was calculated from the level of light-induced quenching of 9-aminoacridine fluorescence. Proton permeability of thylakoid membranes increased during exposure to clino-rotation. When subsequently transferred to darkness, proton efflux increased almost 2-fold in clinorotated leaves. The results were compared with data on pigment and polar lipid composition of photosynthetic membranes in clino-rotated and control plants. It was concluded that both the increase of proton permeability and the decrease of polar lipid content in chloroplasts were induced by clino-rotation.

  18. The complete chloroplast genome sequence of the medicinal plant Andrographis paniculata.

    Science.gov (United States)

    Ding, Ping; Shao, Yanhua; Li, Qian; Gao, Junli; Zhang, Runjing; Lai, Xiaoping; Wang, Deqin; Zhang, Huiye

    2016-07-01

    The complete chloroplast genome of Andrographis paniculata, an important medicinal plant with great economic value, has been studied in this article. The genome size is 150,249 bp in length, with 38.3% GC content. A pair of inverted repeats (IRs, 25,300 bp) are separated by a large single copy region (LSC, 82,459 bp) and a small single-copy region (SSC, 17,190 bp). The chloroplast genome contains 114 unique genes, 80 protein-coding genes, 30 tRNA genes and 4 rRNA genes. In these genes, 15 genes contained 1 intron and 3 genes comprised of 2 introns. PMID:25856518

  19. Complete chloroplast genome sequence of Fritillaria unibracteata var. wabuensis based on SMRT Sequencing Technology.

    Science.gov (United States)

    Li, Ying; Li, Qiushi; Li, Xiwen; Song, Jingyuan; Sun, Chao

    2016-09-01

    Fritillaria unibracteata var. wabuensis is an important medicinal plant used for the treatment of cough symptoms related to the respiratory system. The chloroplast genome of F. unibracteata var. wabuensis (GenBank accession no. KF769142) was assembled using the PacBio RS platform (Pacific Biosciences, Beverly, MA) as a circle sequence with 151 009 bp. The assembled genome contains 133 genes, including 88 protein-coding, 37 tRNA, and eight rRNA genes. This genome sequence will provide important resource for further studies on the evolution of Fritillaria genus and molecular identification of Fritillaria herbs and their adulterants. This work suggests that PacBio RS is a powerful tool to sequence and assemble chloroplast genomes. PMID:26370383

  20. DISRUPTION OF ARABIDOPSIS RETICULON GENE RTNLB16 RESULTS IN CHLOROPLAST DYSFUNCTION AND OXIDATIVE STRESS

    Directory of Open Access Journals (Sweden)

    Tarasenko V.I.

    2012-08-01

    Full Text Available Reticulons (RTNs are endoplasmic reticulum (ER-localized proteins that have recently attracted much attention. RTNs are ubiquitous proteins present in all eukaryotic organisms examined so far. In animal and yeast, in which knowledge of this protein family is more advanced, RTNs are involved in numerous cellular processes such as apoptosis, cell division and intracellular trafficking. Up to now, a little attention has been paid to their plant counterparts, RTNLBs. Meanwhile, gene search across sequenced genomes revealed that the RTN gene family is more diverse and numerous in plants than in animals and yeasts, which possibly suggests existence of functions specific for plant RTNs. Recently, the localization in different ER regions was shown for two members of plant reticulon family. The location in close proximity to chloroplast membrane was revealed for one of RTNLBs, which is argument in favor of its role in interorganellar interactions. In spite of growing interest towards to plant RTNs, there are no investigations devoted to insertion mutagenesis of genes encoding these proteins. We have genotyped an Arabidopsis line containing T-DNA insertion in RTNLB16 gene encoding uncharacterized member of RTNLB family. The obtained homozygous plants have marked phenotype expressed in a decreased growth rate and a pale-green leaf color. The leaf total chlorophyll content as well as the chlorophyll a/b ratio was significantly lower in mutant plants. It is interesting to note that the extent of phenotypic expression depended on a light intensity. The growth rate of wild-type and mutant plants was the same in low light conditions. The growth rate was significantly decreased and chlorophyll content was 3-5-fold lower in mutant plants growing under moderate light conditions. The growing of plants under high light conditions led to halted growth and death of mutants on the seedling stage. The demonstrated phenotype probably points out to a chloroplast

  1. Ascertaining maternal and paternal lineage within Musa by chloroplast and mitochondrial DNA RFLP analyses.

    Science.gov (United States)

    Carreel, F; Gonzalez de Leon, D; Lagoda, P; Lanaud, C; Jenny, C; Horry, J P; Tezenas du Montcel, H

    2002-08-01

    In banana, the maternal transmission of chloroplast DNA and paternal transmission of the mitochondrial DNA provides an exceptional opportunity for studying the maternal and paternal lineage of clones. In the present study, RFLP combined with hybridization of heterologous mitochondrial and chloroplastic probes have been used to characterize 71 wild accessions and 131 diploid and 103 triploid cultivated clones. In additon to Musa acuminata and Musa balbisiana, other species from the four Musa sections were studied to investigate their contribution to the origin of cultivated bananas. These molecular analyses enable the classification of the Musa complex to be discussed. Results ascertain relationships among and between the wild accessions and the mono- and interspecific diploid and triploid bananas, particularly for the acuminata genome. Parthenocarpic varieties are shown to be linked to M. acuminata banksii and M. acuminata errans, thus suggesting that the first center of domestication was in the Philippines - New Guinea area. PMID:12175071

  2. Comparative effects of glyphosate and atrazine in chloroplast ultrastructure of wheat and downy brome

    International Nuclear Information System (INIS)

    Developing and mature leaves of winter wheat (Triticum aestivum L. var. Daws) and the weed species downy brome (Bromus tectorum L.) were subjected to 10 mM (foliar application) and 1 mM (root application) herbicide solutions. Glyphosate (N-(phosphonomethyl) glycine) and atrazine (2-chloro-4-(ethyl-amino)-6-(isopropylamino)-s-triazine) were prepared in a carrier composed of 5% soybean oil concentrate, 35% acetone and 60% water. Penetration experiments with 3H-labelled herbicides assessed what percentage of herbicide entered leaves, and microautoradiography was used to determine qualitatively how much herbicide was present in the sections viewed with TEM. Tissue was excised at 4, 18, 62 and 200 hours, and then either freeze-substituted or fixed chemically. Ultrastructural effects of each herbicide on chloroplasts from leaves of newly-germinated seedlings and of well-tillered plants are depicted and discussed. Temporal differences in response of chloroplasts to each herbicide are noted

  3. The nucleotide sequence of Scenedesmus obliquus chloroplast tRNAfMet.

    OpenAIRE

    McCoy, J M; Jones, D S

    1980-01-01

    The chloroplast initiator tRNAfMet from the green alga Scenedesmus obliquus has been purified and its sequence shown to be p C-G-C-A-G-G-A-U-A-G-A-G-C-A-G-U-C-U-Gm-G-D-A-G-C-U-C-m2(2)G-psi-G-G-G-G-C-U-C-A -U-A-A-psi-C-C-C-A-A-U-m7G-D-C-G-C-A-G-G-T-psi-C-A-A-A-U-C-C-U-G-C-U-C-C-U-G-C-A-A-C-C-A-OH. This structure is prokaryotic in character and displays close homologies with a blue green algal initiator tRNAfMet and bean chloroplast initiator tRNAfMet.

  4. AtDeg2 – a chloroplast protein with dual protease/chaperone activity

    Directory of Open Access Journals (Sweden)

    Przemysław Jagodzik

    2014-07-01

    Full Text Available Chloroplast protease AtDeg2 (an ATP-independent serine endopeptidase is cytosolically synthesized as a precursor, which is imported into the chloroplast stroma and deprived of its transit peptide. Then the mature protein undergoes routing to its functional location at the stromal side of thylakoid membrane. In its linear structure AtDeg2 molecule contains the protease domain with catalytic triad (HDS and two PDZ domains (PDZ1 and PDZ2. In vivo AtDeg2 most probably exists as a supposedly inactive haxamer, which may change its oligomeric stage to form active 12-mer, or 24-mer. AtDeg2 has recently been demonstrated to exhibit dual protease/chaperone function. This review is focused on the current awareness with regard to AtDeg2 structure and functional significance.

  5. Characterization of elemental sulfur in isolated intact spinach chloroplasts. [Spinacia oleracea L

    Energy Technology Data Exchange (ETDEWEB)

    Joyard, J.; Douce, R. (Laboratoire Mixte CNRS/Rhone-Poulenc, Lyon (France)); Forest, E. (Centre d' Etudes Nucleaires de Grenoble (France)); Blee, E. (Institut de Botanique, Strasbourg (France))

    1988-12-01

    Incubation of intact spinach (Spinacia oleracea L.) chloroplasts in the presence of {sup 35}SO{sub 4}{sup 2{minus}} resulted in the light-dependent formation of a chloroform-soluble sulfur-containing compound distinct from sulfolipid. The authors have identified this compound as the most stable form (S{sub 8}) of elemental sulfur (S{sup 0}, valence state for S = O) by mass spectrometry. It is possible that elemental sulfur (S{sup 0}) was formed by oxidation of bound sulfide, i.e. after the photoreduction of sulfate to sulfide by intact chloroplasts, and released as S{sub 8} under the experimental conditions used for analysis.

  6. Light-stimulated transcription of genes for two chloroplast polypeptides in isolated pea leaf nuclei

    OpenAIRE

    Gallagher, Thomas F; Ellis, R. John

    1982-01-01

    Nuclei isolated from both light-grown and dark-grown leaves of Pisum sativum by Percoll density gradient centrifugation incorporate labelled UTP into RNA when supplemented with the other three nucleoside triphosphates. The RNA is heterodisperse, with transcripts up to at least 25S in size. Among these transcripts are sequences hybridizing to cloned DNA probes for wheat rRNA and two abundant chloroplast polypeptides of Pisum, viz. the small subunit of ribulose bisphosphate carboxylase and a po...

  7. Optimization of ATP synthase function in mitochondria and chloroplasts via the adenylate kinase equilibrium

    OpenAIRE

    Igamberdiev, Abir U.; Kleczkowski, Leszek A.

    2015-01-01

    The bulk of ATP synthesis in plants is performed by ATP synthase, the main bioenergetics engine of cells, operating both in mitochondria and in chloroplasts. The reaction mechanism of ATP synthase has been studied in detail for over half a century; however, its optimal performance depends also on the steady delivery of ATP synthase substrates and the removal of its products. For mitochondrial ATP synthase, we analyze here the provision of stable conditions for (i) the supply of ADP and Mg2+, ...

  8. The first complete chloroplast genome sequence of a lycophyte,Huperzia lucidula (Lycopodiaceae)

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, Paul G.; Karol, Kenneth G.; Mandoli, Dina F.; Kuehl,Jennifer V.; Arumuganathan, K.; Ellis, Mark W.; Mishler, Brent D.; Kelch,Dean G.; Olmstead, Richard G.; Boore, Jeffrey L.

    2005-02-01

    We used a unique combination of techniques to sequence the first complete chloroplast genome of a lycophyte, Huperzia lucidula. This plant belongs to a significant clade hypothesized to represent the sister group to all other vascular plants. We used fluorescence-activated cell sorting (FACS) to isolate the organelles, rolling circle amplification (RCA) to amplify the genome, and shotgun sequencing to 8x depth coverage to obtain the complete chloroplast genome sequence. The genome is 154,373bp, containing inverted repeats of 15,314 bp each, a large single-copy region of 104,088 bp, and a small single-copy region of 19,671 bp. Gene order is more similar to those of mosses, liverworts, and hornworts than to gene order for other vascular plants. For example, the Huperziachloroplast genome possesses the bryophyte gene order for a previously characterized 30 kb inversion, thus supporting the hypothesis that lycophytes are sister to all other extant vascular plants. The lycophytechloroplast genome data also enable a better reconstruction of the basaltracheophyte genome, which is useful for inferring relationships among bryophyte lineages. Several unique characters are observed in Huperzia, such as movement of the gene ndhF from the small single copy region into the inverted repeat. We present several analyses of evolutionary relationships among land plants by using nucleotide data, amino acid sequences, and by comparing gene arrangements from chloroplast genomes. The results, while still tentative pending the large number of chloroplast genomes from other key lineages that are soon to be sequenced, are intriguing in themselves, and contribute to a growing comparative database of genomic and morphological data across the green plants.

  9. Chloroplast DNA rearrangements in Campanulaceae: phylogenetic utility of highly rearranged genomes

    Directory of Open Access Journals (Sweden)

    Jansen Robert K

    2004-08-01

    Full Text Available Abstract Background The Campanulaceae (the "hare bell" or "bellflower" family is a derived angiosperm family comprised of about 600 species treated in 35 to 55 genera. Taxonomic treatments vary widely and little phylogenetic work has been done in the family. Gene order in the chloroplast genome usually varies little among vascular plants. However, chloroplast genomes of Campanulaceae represent an exception and phylogenetic analyses solely based on chloroplast rearrangement characters support a reasonably well-resolved tree. Results Chloroplast DNA physical maps were constructed for eighteen representatives of the family. So many gene order changes have occurred among the genomes that characterizing individual mutational events was not always possible. Therefore, we examined different, novel scoring methods to prepare data matrices for cladistic analysis. These approaches yielded largely congruent results but varied in amounts of resolution and homoplasy. The strongly supported nodes were common to all gene order analyses as well as to parallel analyses based on ITS and rbcL sequence data. The results suggest some interesting and unexpected intrafamilial relationships. For example fifteen of the taxa form a derived clade; whereas the remaining three taxa – Platycodon, Codonopsis, and Cyananthus – form the basal clade. This major subdivision of the family corresponds to the distribution of pollen morphology characteristics but is not compatible with previous taxonomic treatments. Conclusions Our use of gene order data in the Campanulaceae provides the most highly resolved phylogeny as yet developed for a plant family using only cpDNA rearrangements. The gene order data showed markedly less homoplasy than sequence data for the same taxa but did not resolve quite as many nodes. The rearrangement characters, though relatively few in number, support robust and meaningful phylogenetic hypotheses and provide new insights into evolutionary

  10. Physiological and Proteomic Analysis in Chloroplasts of Solanum lycopersicum L. under Silicon Efficiency and Salinity Stress

    Directory of Open Access Journals (Sweden)

    Sowbiya Muneer

    2014-11-01

    Full Text Available Tomato plants often grow in saline environments in Mediterranean countries where salt accumulation in the soil is a major abiotic stress that limits its productivity. However, silicon (Si supplementation has been reported to improve tolerance against several forms of abiotic stress. The primary aim of our study was to investigate, using comparative physiological and proteomic approaches, salinity stress in chloroplasts of tomato under silicon supplementation. Tomato seedlings (Solanum lycopersicum L. were grown in nutrient media in the presence or absence of NaCl and supplemented with silicon for 5 days. Salinity stress caused oxidative damage, followed by a decrease in silicon concentrations in the leaves of the tomato plants. However, supplementation with silicon had an overall protective effect against this stress. The major physiological parameters measured in our studies including total chlorophyll and carotenoid content were largely decreased under salinity stress, but were recovered in the presence of silicon. Insufficient levels of net-photosynthesis, transpiration and stomatal conductance were also largely improved by silicon supplementation. Proteomics analysis of chloroplasts analyzed by 2D-BN-PAGE (second-dimensional blue native polyacrylamide-gel electrophoresis revealed a high sensitivity of multiprotein complex proteins (MCPs such as photosystems I (PSI and II (PSII to the presence of saline. A significant reduction in cytochrome b6/f and the ATP-synthase complex was also alleviated by silicon during salinity stress, while the complex forms of light harvesting complex trimers and monomers (LHCs were rapidly up-regulated. Our results suggest that silicon plays an important role in moderating damage to chloroplasts and their metabolism in saline environments. We therefore hypothesize that tomato plants have a greater capacity for tolerating saline stress through the improvement of photosynthetic metabolism and chloroplast proteome

  11. Overexpression of yeast ArDH gene in chloroplasts confers salinity tolerance in plants (abstract)

    International Nuclear Information System (INIS)

    Water stress due to salinity and drought is the main limiting factor for plant growth, productivity and quality. A common response to water deficit is the accumulation of osmoprotectants such as sugars and amino acids. In yeast, arabitol dehydrogenase is found responsible for the production of arabitol from ribulose-5-phosphate. All plants synthesize ribulose-5-phosphate via pentose pathway in chloroplasts.. Therefore, osmotolerance of the plants could be enhanced through metabolic engineering of chloroplasts by introducing ArDH gene into the plastome, which is responsible for the conversion of ribulose-5- phosphate to arabitol. Here we report high-level expression of arabitol dehydrogenase (ArDH) in chloroplasts. Homoplasmic transgenic plants were recovered on spectinomycin-containing regeneration medium. Transformed tobacco plants survived whereas non-transformed were severely stressed or killed when two weeks old seedlings were exposed to NaCl (up to 400 mM), suggesting a role for arabitol in salt tolerance. Seedlings survived up to five weeks on medium containing high salt concentrations (350-400 mM). Nevertheless, seedlings remained green and grew normal on concentrations up to 350 mM NaCl for several weeks. Hypothesis that membranes are protected under stress conditions due to the arabitol accumulation in chloroplasts, seedlings were grown in liquid medium containing polyethylene glycol (PEG, up to 6%). Seedlings were tolerant to 6% PEG, suggesting that ArDH enzyme protects membranes integrity under stress. Therefore, it is concluded that ArDH gene could be expressed in crop plants to withstand abiotic stresses. (author)

  12. Codon reassignment to facilitate genetic engineering and biocontainment in the chloroplast of Chlamydomonas reinhardtii.

    Science.gov (United States)

    Young, Rosanna E B; Purton, Saul

    2016-05-01

    There is a growing interest in the use of microalgae as low-cost hosts for the synthesis of recombinant products such as therapeutic proteins and bioactive metabolites. In particular, the chloroplast, with its small, genetically tractable genome (plastome) and elaborate metabolism, represents an attractive platform for genetic engineering. In Chlamydomonas reinhardtii, none of the 69 protein-coding genes in the plastome uses the stop codon UGA, therefore this spare codon can be exploited as a useful synthetic biology tool. Here, we report the assignment of the codon to one for tryptophan and show that this can be used as an effective strategy for addressing a key problem in chloroplast engineering: namely, the assembly of expression cassettes in Escherichia coli when the gene product is toxic to the bacterium. This problem arises because the prokaryotic nature of chloroplast promoters and ribosome-binding sites used in such cassettes often results in transgene expression in E. coli, and is a potential issue when cloning genes for metabolic enzymes, antibacterial proteins and integral membrane proteins. We show that replacement of tryptophan codons with the spare codon (UGG→UGA) within a transgene prevents functional expression in E. coli and in the chloroplast, and that co-introduction of a plastidial trnW gene carrying a modified anticodon restores function only in the latter by allowing UGA readthrough. We demonstrate the utility of this system by expressing two genes known to be highly toxic to E. coli and discuss its value in providing an enhanced level of biocontainment for transplastomic microalgae. PMID:26471875

  13. The Complete Chloroplast Genome Sequences of Five Epimedium Species: Lights into Phylogenetic and Taxonomic Analyses

    OpenAIRE

    Zhang, Yanjun; Du, Liuwen; Liu, Ao; Chen, Jianjun; Wu, Li; Hu, Weiming; Zhang, Wei; Kim, Kyunghee; Lee, Sang-Choon; Yang, Tae-Jin; Wang, Ying

    2016-01-01

    Epimedium L. is a phylogenetically and economically important genus in the family Berberidaceae. We here sequenced the complete chloroplast (cp) genomes of four Epimedium species using Illumina sequencing technology via a combination of de novo and reference-guided assembly, which was also the first comprehensive cp genome analysis on Epimedium combining the cp genome sequence of E. koreanum previously reported. The five Epimedium cp genomes exhibited typical quadripartite and circular struct...

  14. Viability, ultrastructure and cytokinin metabolism of free and immobilized tobacco chloroplasts

    Czech Academy of Sciences Publication Activity Database

    Polanská, Lenka; Vičánková, Anna; Dobrev, Petre; Macháčková, Ivana; Vaňková, Radomíra

    2004-01-01

    Roč. 26, č. 20 (2004), s. 1549-1555. ISSN 0141-5492 R&D Projects: GA MŠk OC 840.20; GA MŠk LN00A081; GA ČR GA206/03/0369 Institutional research plan: CEZ:AV0Z5038910 Keywords : calcium alginate * chloroplast ultrastructure * cytokinin metabolism Subject RIV: ED - Physiology Impact factor: 0.849, year: 2004

  15. Genesis of grana and stroma thylakoids in leaf chloroplasts of four orchid species

    OpenAIRE

    Barbara Damasz

    2014-01-01

    In the chloroplasts of orchid leaves (Paphiopedilum mastersianum Pfitz., Stanhopea tigrina Batem., Coelogyne cristata LDL and Cymbidium insigne Rolfe) grana stacks differentiate on the base of primary thylakoids. This process occurs by stratification due to overlapping of thylakoids, by their bending and by invagination of the membrane into the thylakoid. There also may form two membranes ending blindly at both ends, called "central contact zone" ("Kontaktzone") in the interior of the mother ...

  16. Relationships of wild and domesticated rices (Oryza AA genome species) based upon whole chloroplast genome sequences

    OpenAIRE

    Wambugu, Peterson W.; Marta Brozynska; Agnelo Furtado; Daniel L. Waters; Robert J. Henry

    2015-01-01

    Rice is the most important crop in the world, acting as the staple food for over half of the world’s population. The evolutionary relationships of cultivated rice and its wild relatives have remained contentious and inconclusive. Here we report on the use of whole chloroplast sequences to elucidate the evolutionary and phylogenetic relationships in the AA genome Oryza species, representing the primary gene pool of rice. This is the first study that has produced a well resolved and strongly su...

  17. Unbiased estimation of chloroplast number in mesophyll cells: advantage of a genuine three-dimensional approach

    Czech Academy of Sciences Publication Activity Database

    Kubínová, Z.; Janáček, Jiří; Lhotáková, Z.; Kubínová, Lucie; Albrechtová, J.

    2014-01-01

    Roč. 65, č. 2 (2014), s. 609-620. ISSN 0022-0957 R&D Projects: GA ČR(CZ) GAP501/10/0340 Grant ostatní: Univerzita Karlova(CZ) SVV265203 Institutional research plan: CEZ:AV0Z50110509 Institutional support: RVO:67985823 Keywords : chloroplast counting * confocal microscopy * disector method * mesophyll * coniferous needle structure * Norway spruce (Picea abies L. Karst.), * profile counting * stereology Subject RIV: GK - Forestry Impact factor: 5.526, year: 2014

  18. A Set of 100 Chloroplast DNA Primer Pairs to Study Population Genetics and Phylogeny in Monocotyledons

    OpenAIRE

    Scarcelli, Nora; Barnaud, Adeline; Eiserhardt, Wolf; Treier, Urs A.; Seveno, Marie; d'Anfray, Amélie; Vigouroux, Yves; Pintaud, Jean-Christophe

    2011-01-01

    Chloroplast DNA sequences are of great interest for population genetics and phylogenetic studies. However, only a small set of markers are commonly used. Most of them have been designed for amplification in a large range of Angiosperms and are located in the Large Single Copy (LSC). Here we developed a new set of 100 primer pairs optimized for amplification in Monocotyledons. Primer pairs amplify coding (exon) and non-coding regions (intron and intergenic spacer). They span the different chlo...

  19. Chloroplast redox imbalance governs phenotypic plasticity: the “grand design of photosynthesis” revisited

    OpenAIRE

    Hüner, Norman P. A.; Bode, Rainer; Dahal, Keshav; Hollis, Lauren; Rosso, Dominic; Krol, Marianna; Ivanov, Alexander G.

    2012-01-01

    Sunlight, the ultimate energy source for life on our planet, enters the biosphere as a direct consequence of the evolution of photoautotrophy. Photoautotrophs must balance the light energy absorbed and trapped through extremely fast, temperature-insensitive photochemistry with energy consumed through much slower, temperature-dependent biochemistry and metabolism. The attainment of such a balance in cellular energy flow between chloroplasts, mitochondria and the cytosol is called photostasis. ...

  20. Maize mutants lacking chloroplast FtsY exhibit pleiotropic defects in the biogenesis of thylakoid membranes.

    Science.gov (United States)

    Asakura, Yukari; Hirohashi, Toshiya; Kikuchi, Shingo; Belcher, Susan; Osborne, Erin; Yano, Satoshi; Terashima, Ichiro; Barkan, Alice; Nakai, Masato

    2004-01-01

    A chloroplast signal recognition particle (SRP) that is related to the SRP involved in secretion in bacteria and eukaryotic cells is used for the insertion of light-harvesting chlorophyll proteins (LHCPs) into the thylakoid membranes. A conserved component of the SRP mechanism is a membrane-bound SRP receptor, denoted FtsY in bacteria. Plant genomes encode FtsY homologs that are targeted to the chloroplast (cpFtsY). To investigate the in vivo roles of cpFtsY, we characterized maize cpFtsY and maize mutants having a Mu transposon insertion in the corresponding gene (chloroplast SRP receptor1, or csr1). Maize cpFtsY accumulates to much higher levels in leaf tissue than in roots and stems. Interestingly, it is present at similar levels in etiolated and green leaf tissue and was found to bind the prolamellar bodies of etioplasts. A null cpFtsY mutant, csr1-1, showed a substantial loss of leaf chlorophyll, whereas a "leaky" allele, csr1-3, conditioned a more moderate chlorophyll deficiency. Both alleles caused the loss of various LHCPs and the thylakoid-bound photosynthetic enzyme complexes and were seedling lethal. By contrast, levels of the membrane-bound components of the thylakoid protein transport machineries were not altered. The thylakoid membranes in csr1-1 chloroplasts were unstacked and reduced in abundance, but the prolamellar bodies in mutant etioplasts appeared normal. These results demonstrate the essentiality of cpFtsY for the biogenesis not only of the LHCPs but also for the assembly of the other membrane-bound components of the photosynthetic apparatus. PMID:14688289

  1. Algal chloroplast produced camelid VHH antitoxins are capable of neutralizing botulinum neurotoxin

    OpenAIRE

    Daniel J Barrera; Rosenberg, Julian N.; Chiu, Joanna G.; Chang, Yung-Nien; Debatis, Michelle; Ngoi, Soo-Mun; Chang, John T.; Shoemaker, Charles B.; George A Oyler; Mayfield, Stephen P

    2014-01-01

    We have produced three antitoxins consisting of the variable domains of camelid heavy chain-only antibodies (VHH) by expressing the genes in the chloroplast of green algae. These antitoxins accumulate as soluble proteins capable of binding and neutralizing botulinum neurotoxin. Furthermore, they accumulate at up to 5% total soluble protein, sufficient expression to easily produce these antitoxins at scale from algae. The genes for the three different antitoxins were transformed into Chlamydom...

  2. The complete chloroplast and mitochondrial genomes of the green macroalga Ulva sp. UNA00071828 (Ulvophyceae, Chlorophyta.

    Directory of Open Access Journals (Sweden)

    James T Melton

    Full Text Available Sequencing mitochondrial and chloroplast genomes has become an integral part in understanding the genomic machinery and the phylogenetic histories of green algae. Previously, only three chloroplast genomes (Oltmannsiellopsis viridis, Pseudendoclonium akinetum, and Bryopsis hypnoides and two mitochondrial genomes (O. viridis and P. akinetum from the class Ulvophyceae have been published. Here, we present the first chloroplast and mitochondrial genomes from the ecologically and economically important marine, green algal genus Ulva. The chloroplast genome of Ulva sp. was 99,983 bp in a circular-mapping molecule that lacked inverted repeats, and thus far, was the smallest ulvophycean plastid genome. This cpDNA was a highly compact, AT-rich genome that contained a total of 102 identified genes (71 protein-coding genes, 28 tRNA genes, and three ribosomal RNA genes. Additionally, five introns were annotated in four genes: atpA (1, petB (1, psbB (2, and rrl (1. The circular-mapping mitochondrial genome of Ulva sp. was 73,493 bp and follows the expanded pattern also seen in other ulvophyceans and trebouxiophyceans. The Ulva sp. mtDNA contained 29 protein-coding genes, 25 tRNA genes, and two rRNA genes for a total of 56 identifiable genes. Ten introns were annotated in this mtDNA: cox1 (4, atp1 (1, nad3 (1, nad5 (1, and rrs (3. Double-cut-and-join (DCJ values showed that organellar genomes across Chlorophyta are highly rearranged, in contrast to the highly conserved organellar genomes of the red algae (Rhodophyta. A phylogenomic investigation of 51 plastid protein-coding genes showed that Ulvophyceae is not monophyletic, and also placed Oltmannsiellopsis (Oltmannsiellopsidales and Tetraselmis (Chlorodendrophyceae closely to Ulva (Ulvales and Pseudendoclonium (Ulothrichales.

  3. Chloroplast-derived enzyme cocktails hydrolyse lignocellulosic biomass and release fermentable sugars

    OpenAIRE

    Verma, Dheeraj; Kanagaraj, Anderson; Jin, Shuangxia; Singh, Nameirakpam D.; Kolattukudy, Pappachan E.; Daniell, Henry

    2010-01-01

    It is widely recognized that biofuel production from lignocellulosic materials is limited by inadequate technology to efficiently and economically release fermentable sugars from the complex multi-polymeric raw materials. Therefore, endoglucanases, exoglucanase, pectate lyases, cutinase, swollenin, xylanase, acetyl xylan esterase, beta glucosidase and lipase genes from bacteria or fungi were expressed in E. coli or tobacco chloroplasts. A PCR based method was used to clone genes without intro...

  4. Translational coupling of the maize chloroplast atpB and atpE genes

    OpenAIRE

    Gatenby, Anthony A.; Rothstein, Steven. J.; Nomura, Masayasu

    1989-01-01

    The genes for the β and ε subunits of maize chloroplast ATP synthase are encoded by the organelle genome, are cotranscribed, and have overlapping translation initiation and termination codons. To determine whether the atpB and atpE genes are translationally coupled, they were transformed into Escherichia coli on a multicopy plasmid. Synthesis of full-length β and ε polypeptides demonstrated correct initiation of translation by the bacterial ribosomes. To assay for translational coupling, the ...

  5. Uncovering the Protein Lysine and Arginine Methylation Network in Arabidopsis Chloroplasts

    OpenAIRE

    Alban, Claude; Tardif, Marianne; Mininno, Morgane; Brugiere, Sabine; Gilgen, Annabelle; Ma, Sheng; Mazzoleni, Meryl; Gigarel, Oceane; Martin-Laffon, Jacqueline; Ferro, Myriam

    2014-01-01

    Post-translational modification of proteins by the addition of methyl groups to the side chains of Lys and Arg residues is proposed to play important roles in many cellular processes. In plants, identification of non-histone methylproteins at a cellular or subcellular scale is still missing. To gain insights into the extent of this modification in chloroplasts we used a bioinformatics approach to identify protein methyltransferases targeted to plastids and set up a workflow to specifically id...

  6. Characterization of a prokaryotic topoisomerase I activity in chloroplast extracts from spinach.

    OpenAIRE

    Siedlecki, J; Zimmermann, W.; Weissbach, A

    1983-01-01

    A topoisomerase I activity has been partially purified from crude extracts of spinach chloroplasts. This activity relaxes the supercoiled covalently closed circular DNA of pBR322. The enzyme requires Mg++, but not ATP, and has an apparent molecular weight of about 115,000. It catalyzes a unit change in the linkage number of supercoiled DNA but cannot relax positive supercoiled DNA. These characteristics of the topoisomerase suggest it is of the prokaryotic type and would tend to support the e...

  7. Expression of dengue-3 premembrane and envelope polyprotein in lettuce chloroplasts.

    Science.gov (United States)

    Kanagaraj, Anderson Paul; Verma, Dheeraj; Daniell, Henry

    2011-07-01

    Dengue is an acute febrile viral disease with >100 million infections occurring each year and more than half of the world population is at risk. Global resurgence of dengue in many urban centers of the tropics is a major concern. Therefore, development of a successful vaccine is urgently needed that is economical and provide long-lasting protection from dengue virus infections. In this manuscript, we report expression of dengue-3 serotype polyprotein (prM/E) consisting of part of capsid, complete premembrane (prM) and truncated envelope (E) protein in an edible crop lettuce. The dengue sequence was controlled by endogenous Lactuca sativa psbA regulatory elements. PCR and Southern blot analysis confirmed transgene integration into the lettuce chloroplast genome via homologous recombination at the trnI/trnA intergenic spacer region. Western blot analysis showed expression of polyprotein prM/E in different forms as monomers (~65 kDa) or possibly heterodimers (~130 kDa) or multimers. Multimers were solubilized into monomers using guanidine hydrochloride. Transplastomic lettuce plants expressing dengue prM/E vaccine antigens grew normally and transgenes were inherited in the T1 progeny without any segregation. Transmission electron microscopy showed the presence of virus-like particles of ~20 nm diameter in chloroplast extracts of transplastomic lettuce expressing prM/E proteins, but not in untransformed plants. The prM/E antigens expressed in lettuce chloroplasts should offer a potential source for investigating an oral Dengue vaccine. PMID:21431782

  8. Photosynthetic Characteristics and Ultrastructure of Chloroplast of Cucumber Under Low Light Density in Solar-Greenhouse

    Institute of Scientific and Technical Information of China (English)

    AI Xi-zhen; GUO Yan-kui; CHEN Li-ping; XING Yu-xian

    2004-01-01

    The photosynthetic characteristics and ultrastructure of chloroplast of cucumber in solargreenhouse were studied. The result showed that the photosynthetic rate (Pn), photosynthetic ability (A350), carboxylation efficiency, light saturation point and light compensation point all declined remarkably under lowlight density, indicating that the photosynthetic characteristics of cucumber were closely related to light environment. Under iow light density, the minimal fluorescence (Fo), alterable fluorescence (Fv), photochemical efficiency of PS Ⅱ (Fv/Fm), steady fluorescence in light (Fs), maximal fluorescence (Fm′) and actual efficiency of PS Ⅱ (φPSⅡ)etc increased, indicating that the photochemical activity and efficiency for solar energy transformation enhanced, thus the light proportion used to electron transport also increased. The chlorophyll a, b, a/b and carotenoid of shading leaves decreased. However, the depressed extent of Chl a and Chl a/b were obviously larger than that of Chl b. The number of chloroplast and starch grain in cucumber leaves descended, but that of grana and lamella increased as a shaded result. The size of chloroplast and starch grain of shading leaves minished.

  9. Phylogeny of the genus Pistacia as determined from analysis of the chloroplast genome.

    Science.gov (United States)

    Parfitt, D E; Badenes, M L

    1997-07-22

    Classification within the genus Pistacia has been based on leaf morphology and geographical distribution. Molecular genetic tools (PCR amplification followed by restriction analysis of a 3.2-kb region of variable chloroplast DNA, and restriction fragment length polymorphism analysis of the Pistacia cpDNA with tobacco chloroplast DNA probes) provided a new set of variables to study the phylogenetic relationships of 10 Pistacia species. Both parsimony and cluster analyses were used to divide the genus into two major groups. P. vera was determined to be the least derived species. P. weinmannifolia, an Asian species, is most closely related to P. texana and P. mexicana, New World species. These three species share a common origin, suggesting that a common ancestor of P. texana and P. mexicana originated in Asia. P. integerrima and P. chinensis were shown to be distinct whereas the pairs of species were monophyletic within each of two tertiary groups, P. vera:P. khinjuk and P. mexicana:P. texana. An evolutionary trend from large to small nuts and leaves with few, large leaflets to many, small leaflets was supported. The genus Pistacia was shown to have a low chloroplast DNA mutation rate: 0.05-0.16 times that expected of annual plants. PMID:9223300

  10. Phylogenomic analysis of transcriptomic sequences of mitochondria and chloroplasts for marine red algae (Rhodophyta) in China

    Institute of Scientific and Technical Information of China (English)

    JIA Shangang; LIU Tao; WU Shuangxiu; WANG Xumin; QIAN Hao; LI Tianyong; SUN Jing; WANG Liang; YU Jun; LI Xingang; YIN Jinlong

    2014-01-01

    The chloroplast and mitochondrion of red algae (Phylum Rhodophyta) may have originated from different endosymbiosis. In this study, we carried out phylogenomic analysis to distinguish their evolutionary lin-eages by using red algal RNA-seq datasets of the 1 000 Plants (1KP) Project and publicly available complete genomes of mitochondria and chloroplasts of Rhodophyta. We have found that red algae were divided into three clades of orders, Florideophyceae, Bangiophyceae and Cyanidiophyceae. Taxonomy resolution for Class Florideophyceae showed that Order Gigartinales was close to Order Halymeniales, while Order Graci-lariales was in a clade of Order Ceramials. We confirmed Prionitis divaricata (Family Halymeniaceae) was closely related to the clade of Order Gracilariales, rather than to genus Grateloupia of Order Halymeniales as reported before. Furthermore, we found both mitochondrial and chloroplastic genes in Rhodophyta under negative selection (Ka/Ks<1), suggesting that red algae, as one primitive group of eukaryotic algae, might share joint evolutionary history with these two organelles for a long time, although we identified some dif-ferences in their phylogenetic trees. Our analysis provided the basic phylogenetic relationships of red algae, and demonstrated their potential ability to study endosymbiotic events.

  11. Chloroplast osmotic adjustment allows for acclimation of photosynthesis to low water potentials

    International Nuclear Information System (INIS)

    Previously in this laboratory, studies indicated that photosynthesis (PS) of chloroplasts isolated from spinach plants which underwent osmotic adjustment during in situ water deficits was inhibited less at low osmotic potentials (Psi/sub s/) in vitro than PS of plastids isolated from well watered plants. In this study, an attempt was made to determine if chloroplast acclimation to low Psi/sub s/ was associated with in situ stromal solute accumulation. During a 14d stress cycle, in situ stromal volume was estimated by measuring (using the 3H2O, 14C-sorbitol silicon oil centrifugation technique) the stromal space of plastids in solutions which had the Psi/sub s/ adjusted to the leaf Psi/sub s/. During the first lid of the cycle, stromal volume did not decline, despite a decrease of over 20% in the leaf RWC. After this time, stromal volume dropped rapidly. In situ stromal Psi/sub s/ was also estimated during a stress cycle. These studies indicated that stromal Psi/sub s/ was lowered by net solute accumulation. The data presented in this report suggest that chloroplast acclimation to low Psi/sub s/ may involve stromal solute accumulation and volume maintenance during cell water loss

  12. Stress tolerance of transgenic barley accumulating the alfalfa aldose reductase in the cytoplasm and the chloroplast.

    Science.gov (United States)

    Nagy, Bettina; Majer, Petra; Mihály, Róbert; Pauk, János; Horváth, Gábor V

    2016-09-01

    Barley represents one of the major crops grown worldwide; its genetic transformation provides an important tool for the improvement of crop quality and tolerance to environmental stress factors. Biotic and abiotic stresses produce reactive oxygen species in the plant cells that can directly oxidize the cellular components including lipid membranes; resulting in lipid peroxidation and subsequently the accumulation of reactive carbonyl compounds. In order to protect barley plants from the effects of stress-produced reactive carbonyls, an Agrobacterium-mediated transformation was carried out using the Medicago sativa aldose reductase (MsALR) gene. In certain transgenic lines the produced MsALR enzyme was targeted to the chloroplasts to evaluate its protective effect in these organelles. The dual fluorescent protein-based method was used for the evaluation of tolerance of young seedlings to diverse stresses; our results demonstrated that this technique could be reliably applied for the detection of cellular stress in a variety of conditions. The chlorophyll and carotenoid content measurements also supported the results of the fluorescent protein-based method and the stress-protective effect of the MsALR enzyme. Targeting of MsALR into the chloroplast has also resulted in increased stress tolerance, similarly to the observed effect of the cytosolic MsALR accumulation. The results of the DsRed/GFP fluorescent protein-based method indicated that both the cytosol and chloroplast accumulation of MsALR can increase the abiotic stress tolerance of transgenic barley lines. PMID:27469099

  13. 2010 GORDON RESEARCH CONFERENCE ON MITOCHONDRIA & CHLOROPLASTS, LUCCA, ITALY, JULY 11-16, 2010

    Energy Technology Data Exchange (ETDEWEB)

    Alice Barkan

    2010-07-16

    The 2010 GRC on Mitochondria & Chloroplasts will assemble an international group of molecular, structural and cellular biologists, biochemists and geneticists investigating a broad spectrum of fundamental problems related to the biology of these organelles in animal, plant and fungal cells. This field has witnessed an extraordinary expansion in recent years, fueled by the discovery of the role of mitochondria in human disease and ageing, and of the synergy of chloroplasts and mitochondria in energetic output, the identification of novel factors involved in organelle division, movement, signaling and acclimation to changing environmental conditions, and by the powerful tools of organelle proteomics. The 2010 GRC will highlight advances in the elucidation of molecular mechanisms of organelle biogenesis including regulation of genome structure, evolution and expression, organellar protein import, assembly and turnover of respiratory and photosynthetic complexes, bidirectional signaling between organelles and nucleus, organelle morphology and dynamics, and the integration of cellular metabolism. We will also explore progress in mechanisms of disease and ageing/ senescence in animals and plants. The organellar field has forged new fronts toward a global and comprehensive understanding of mitochondrial and chloroplast biology at the molecular level. Many of the molecules under study in model organisms are responsible for human diseases, providing significant impetus for a meeting that encourages interactions between mammalian, fungal and plant organellar biologists.

  14. Developmental changes in aspartate-family amino acid biosynthesis in pea chloroplasts

    International Nuclear Information System (INIS)

    Isolated chloroplasts are known to synthesize the asp-derived amino acids (ile, hse, lys and thr) from [14C]asp (Mills et al, 1980, Plant Physiol. 65, 1166). Now, we have studied the influence of tissue age on essential amino acid biosynthesis in pea (Pisum sativum) plastids. Chloroplasts from the younger (third and fourth) leaves of 12 day old plants, were 2-3 times more active in synthesizing lys and thr from [14C]asp than those from older (first or second) leaves. We also examined two key pathway enzymes (aspartate kinase and homoserine dehydrogenase); with each enzyme,a activity in younger leaves was about 2 times that in plastids from older tissue. Both lys- and thr-sensitive forms of aspartate kinase are known in plants; in agreement with earlier work, we found that lys-sensitive activity was about 4 times higher in the younger tissues, while the thr-sensitive activity changed little during development (Davies and Miflin, 1977, Plant Sci. Lett. 9, 323). Recently the role of aspartate kinase and homoserine dehydrogenase in controlling asp-family amino acid synthesis has been questioned (Giovanelli et al, 1989, Plant Physiol. 90, 1584); we hope that measurements of amino acid levels in chloroplasts as well as further enzyme studies will help us to better understand the regulation of asp-family amino acid synthesis

  15. Complete chloroplast genome of Trachelium caeruleum: extensiverearrangements are associated with repeats and tRNAs

    Energy Technology Data Exchange (ETDEWEB)

    Haberle, Rosemarie C.; Fourcade, Matthew L.; Boore, Jeffrey L.; Jansen, Robert K.

    2006-01-09

    Chloroplast genome structure, gene order and content arehighly conserved in land plants. We sequenced the complete chloroplastgenome sequence of Trachelium caeruleum (Campanulaceae) a member of anangiosperm family known for highly rearranged chloroplast genomes. Thetotal genome size is 162,321 bp with an IR of 27,273 bp, LSC of 100,113bp and SSC of 7,661 bp. The genome encodes 115 unique genes, with 19duplicated in the IR, a tRNA (trnI-CAU) duplicated once in the LSC and aprotein coding gene (psbJ) duplicated twice, for a total of 137 genes.Four genes (ycf15, rpl23, infA and accD) are truncated and likelynonfunctional; three others (clpP, ycf1 and ycf2) are so highly divergedthat they may now be pseudogenes. The most conspicuous feature of theTrachelium genome is the presence of eighteen internally unrearrangedblocks of genes that have been inverted or relocated within the genome,relative to the typical gene order of most angiosperm chloroplastgenomes. Recombination between repeats or tRNAs has been suggested as twomeans of chloroplast genome rearrangements. We compared the relativenumber of repeats in Trachelium to eight other angiosperm chloroplastgenomes, and evaluated the location of repeats and tRNAs in relation torearrangements. Trachelium has the highest number and largest repeats,which are concentrated near inversion endpoints or other rearrangements.tRNAs occur at many but not all inversion endpoints. There is likely nosingle mechanism responsible for the remarkable number of alterations inthis genome, but both repeats and tRNAs are clearly associated with theserearrangements. Land plant chloroplast genomes are highly conserved instructure, gene order and content. The chloroplast genomes of ferns, thegymnosperm Ginkgo, and most angiosperms are nearly collinear, reflectingthe gene order in lineages that diverged from lycopsids and the ancestralchloroplast gene order over 350 million years ago (Raubeson and Jansen,1992). Although earlier mapping studies

  16. The chloroplast genome of the hexaploid Spartina maritima (Poaceae, Chloridoideae): Comparative analyses and molecular dating.

    Science.gov (United States)

    Rousseau-Gueutin, M; Bellot, S; Martin, G E; Boutte, J; Chelaifa, H; Lima, O; Michon-Coudouel, S; Naquin, D; Salmon, A; Ainouche, K; Ainouche, M

    2015-12-01

    The history of many plant lineages is complicated by reticulate evolution with cases of hybridization often followed by genome duplication (allopolyploidy). In such a context, the inference of phylogenetic relationships and biogeographic scenarios based on molecular data is easier using haploid markers like chloroplast genome sequences. Hybridization and polyploidization occurred recurrently in the genus Spartina (Poaceae, Chloridoideae), as illustrated by the recent formation of the invasive allododecaploid S. anglica during the 19th century in Europe. Until now, only a few plastid markers were available to explore the history of this genus and their low variability limited the resolution of species relationships. We sequenced the complete chloroplast genome (plastome) of S. maritima, the native European parent of S. anglica, and compared it to the plastomes of other Poaceae. Our analysis revealed the presence of fast-evolving regions of potential taxonomic, phylogeographic and phylogenetic utility at various levels within the Poaceae family. Using secondary calibrations, we show that the tetraploid and hexaploid lineages of Spartina diverged 6-10 my ago, and that the two parents of the invasive allopolyploid S. anglica separated 2-4 my ago via long distance dispersal of the ancestor of S. maritima over the Atlantic Ocean. Finally, we discuss the meaning of divergence times between chloroplast genomes in the context of reticulate evolution. PMID:26182838

  17. RNA Editing Sites Exist in Protein-coding Genes in the Chloroplast Genome of Cycas taitungensis

    Institute of Scientific and Technical Information of China (English)

    Haiyan Chen; Likun Deng; Yuan Jiang; Ping Lu; Jianing Yu

    2011-01-01

    RNA editing is a post-transcriptional process that results in modifications of ribonucleotides at specific locations.In land plants editing can occur in both mitochondria and chloroplasts and most commonly involves C-to-U changes,especially in seed plants.Using prediction and experimental determination,we investigated RNA editing in 40 protein-coding genes from the chloroplast genome of Cycas taitungensis.A total of 85 editing sites were identified in 25 transcripts.Comparison analysis of the published editotypes of these 25 transcripts in eight species showed that RNA editing events gradually disappear during plant evolution.The editing in the first and third codon position disappeared quicker than that in the second codon position,ndh genes have the highest editing frequency while serine and proline codons were more frequently edited than the codons of other amino acids.These results imply that retained RNA editing sites have imbalanced distribution in genes and most of them may function by changing protein structure or interaction.Mitochondrion protein-coding genes have three times the editing sites compared with chloroplast genes of Cycas,most likely due to slower evolution speed.

  18. Proton Gradients and Proton-Dependent Transport Processes in the Chloroplast

    Science.gov (United States)

    Höhner, Ricarda; Aboukila, Ali; Kunz, Hans-Henning; Venema, Kees

    2016-01-01

    Proton gradients are fundamental to chloroplast function. Across thylakoid membranes, the light induced -proton gradient is essential for ATP synthesis. As a result of proton pumping into the thylakoid lumen, an alkaline stromal pH develops, which is required for full activation of pH-dependent Calvin Benson cycle enzymes. This implies that a pH gradient between the cytosol (pH 7) and the stroma (pH 8) is established upon illumination. To maintain this pH gradient chloroplasts actively extrude protons. More than 30 years ago it was already established that these proton fluxes are electrically counterbalanced by Mg2+, K+, or Cl- fluxes, but only recently the first transport systems that regulate the pH gradient were identified. Notably several (Na+,K+)/H+ antiporter systems where identified, that play a role in pH gradient regulation, ion homeostasis, osmoregulation, or coupling of secondary active transport. The established pH gradients are important to drive uptake of essential ions and solutes, but not many transporters involved have been identified to date. In this mini review we summarize the current status in the field and the open questions that need to be addressed in order to understand how pH gradients are maintained, how this is interconnected with other transport processes and what this means for chloroplast function. PMID:26973667

  19. Chloroplast SSR polymorphisms in the Compositae and the mode of organellar inheritance in Helianthus annuus.

    Science.gov (United States)

    Wills, David M; Hester, Melissa L; Liu, Aizhong; Burke, John M

    2005-03-01

    Because organellar genomes are often uniparentally inherited, chloroplast (cp) and mitochondrial (mt) DNA polymorphisms have become the markers of choice for investigating evolutionary issues such as sex-biased dispersal and the directionality of introgression. To the extent that organellar inheritance is strictly maternal, it has also been suggested that the insertion of transgenes into either the chloroplast or mitochondrial genomes would reduce the likelihood of gene escape via pollen flow from crop fields into wild plant populations. In this paper we describe the adaptation of chloroplast simple sequence repeats (cpSSRs) for use in the Compositae. This work resulted in the identification of 12 loci that are variable across the family, seven of which were further shown to be highly polymorphic within sunflower (Helianthus annuus). We then used these markers, along with a novel mtDNA restriction fragment length polymorphism (RFLP), to investigate the mode of organellar inheritance in a series of experimental crosses designed to mimic the initial stages of crop-wild hybridization in sunflower. Although we cannot rule out the possibility of extremely rare paternal transmission, our results provide the best evidence to date of strict maternal organellar inheritance in sunflower, suggesting that organellar gene containment may be a viable strategy in sunflower. Moreover, the portability of these markers suggests that they will provide a ready source of cpDNA polymorphisms for use in evolutionary studies across the Compositae. PMID:15690173

  20. Comparative proteomic analysis of amaranth mesophyll and bundle sheath chloroplasts and their adaptation to salt stress.

    Science.gov (United States)

    Joaquín-Ramos, Ahuitzolt; Huerta-Ocampo, José Á; Barrera-Pacheco, Alberto; De León-Rodríguez, Antonio; Baginsky, Sacha; Barba de la Rosa, Ana P

    2014-09-15

    The effect of salt stress was analyzed in chloroplasts of Amaranthus cruentus var. Amaranteca, a plant NAD-malic enzyme (NAD-ME) type. Morphology of chloroplasts from bundle sheath (BSC) and mesophyll (MC) was observed by transmission electron microscopy (TEM). BSC and MC from control plants showed similar morphology, however under stress, changes in BSC were observed. The presence of ribulose bisphosphate carboxylase/oxygenase (RuBisCO) was confirmed by immunohistochemical staining in both types of chloroplasts. Proteomic profiles of thylakoid protein complexes from BSC and MC, and their changes induced by salt stress were analyzed by blue-native polyacrylamide gel electrophoresis followed by SDS-PAGE (2-D BN/SDS-PAGE). Differentially accumulated protein spots were analyzed by LC-MS/MS. Although A. cruentus photosynthetic tissue showed the Kranz anatomy, the thylakoid proteins showed some differences at photosystem structure level. Our results suggest that A. cruentus var. Amaranteca could be better classified as a C3-C4 photosynthetic plant. PMID:25046763

  1. Complete Chloroplast Genome of the Wollemi Pine (Wollemia nobilis: Structure and Evolution.

    Directory of Open Access Journals (Sweden)

    Jia-Yee S Yap

    Full Text Available The Wollemi pine (Wollemia nobilis is a rare Southern conifer with striking morphological similarity to fossil pines. A small population of W. nobilis was discovered in 1994 in a remote canyon system in the Wollemi National Park (near Sydney, Australia. This population contains fewer than 100 individuals and is critically endangered. Previous genetic studies of the Wollemi pine have investigated its evolutionary relationship with other pines in the family Araucariaceae, and have suggested that the Wollemi pine genome contains little or no variation. However, these studies were performed prior to the widespread use of genome sequencing, and their conclusions were based on a limited fraction of the Wollemi pine genome. In this study, we address this problem by determining the entire sequence of the W. nobilis chloroplast genome. A detailed analysis of the structure of the genome is presented, and the evolution of the genome is inferred by comparison with the chloroplast sequences of other members of the Araucariaceae and the related family Podocarpaceae. Pairwise alignments of whole genome sequences, and the presence of unique pseudogenes, gene duplications and insertions in W. nobilis and Araucariaceae, indicate that the W. nobilis chloroplast genome is most similar to that of its sister taxon Agathis. However, the W. nobilis genome contains an unusually high number of repetitive sequences, and these could be used in future studies to investigate and conserve any remnant genetic diversity in the Wollemi pine.

  2. Accumulation and processing of a recombinant protein designed as a cleavable fusion to the endogenous Rubisco LSU protein in Chlamydomonas chloroplast

    OpenAIRE

    Henry Ryan E; Muto Machiko; Mayfield Stephen P

    2009-01-01

    Abstract Background Expression of recombinant proteins in green algal chloroplast holds substantial promise as a platform for the production of human therapeutic proteins. A number of proteins have been expressed in the chloroplast of Chlamydomonas reinhardtii, including complex mammalian proteins, but many of these proteins accumulate to significantly lower levels than do endogenous chloroplast proteins. We examined if recombinant protein accumulation could be enhanced by genetically fusing ...

  3. A novel class of heat-responsive small RNAs derived from the chloroplast genome of Chinese cabbage (Brassica rapa

    Directory of Open Access Journals (Sweden)

    de Ruiter Marjo

    2011-06-01

    Full Text Available Abstract Background Non-coding small RNAs play critical roles in various cellular processes in a wide spectrum of eukaryotic organisms. Their responses to abiotic stress have become a popular topic of economic and scientific importance in biological research. Several studies in recent years have reported a small number of non-coding small RNAs that map to chloroplast genomes. However, it remains uncertain whether small RNAs are generated from chloroplast genome and how they respond to environmental stress, such as high temperature. Chinese cabbage is an important vegetable crop, and heat stress usually causes great losses in yields and quality. Under heat stress, the leaves become etiolated due to the disruption and disassembly of chloroplasts. In an attempt to determine the heat-responsive small RNAs in chloroplast genome of Chinese cabbage, we carried out deep sequencing, using heat-treated samples, and analysed the proportion of small RNAs that were matched to chloroplast genome. Results Deep sequencing provided evidence that a novel subset of small RNAs were derived from the chloroplast genome of Chinese cabbage. The chloroplast small RNAs (csRNAs include those derived from mRNA, rRNA, tRNA and intergenic RNA. The rRNA-derived csRNAs were preferentially located at the 3'-ends of the rRNAs, while the tRNA-derived csRNAs were mainly located at 5'-termini of the tRNAs. After heat treatment, the abundance of csRNAs decreased in seedlings, except those of 24 nt in length. The novel heat-responsive csRNAs and their locations in the chloroplast were verified by Northern blotting. The regulation of some csRNAs to the putative target genes were identified by real-time PCR. Our results reveal that high temperature suppresses the production of some csRNAs, which have potential roles in transcriptional or post-transcriptional regulation. Conclusions In addition to nucleus, the chloroplast is another important organelle that generates a number of small

  4. Conservation of shh cis-regulatory architecture of the coelacanth is consistent with its ancestral phylogenetic position

    Directory of Open Access Journals (Sweden)

    Lang Michael

    2010-11-01

    Full Text Available Abstract Background The modern coelacanth (Latimeria is the extant taxon of a basal sarcopterygian lineage and sister group to tetrapods. Apart from certain apomorphic traits, its morphology is characterized by a high degree of retention of ancestral vertebrate structures and little morphological change. An insight into the molecular evolution that may explain the unchanged character of Latimeria morphology requires the analysis of the expression patterns of developmental regulator genes and their cis-regulatory modules (CRMs. Results We describe the comparative and functional analysis of the sonic hedgehog (shh genomic region of Latimeria menadoensis. Several putative enhancers in the Latimeria shh locus have been identified by comparisons to sarcopterygian and actinopterygian extant species. Specific sequence conservation with all known actinopterygian enhancer elements has been detected. However, these elements are selectively missing in more recently diverged actinopterygian and sarcopterygian species. The functionality of the putative Latimeria enhancers was confirmed by reporter gene expression analysis in transient transgenic zebrafish and chick embryos. Conclusions Latimeria shh CRMs represent the ancestral set of enhancers that have emerged before the split of lobe-finned and ray-finned fishes. In contrast to lineage-specific losses and differentiations in more derived lineages, Latimeria shh enhancers reveal low levels of sequence diversification. High overall sequence conservation of shh conserved noncoding elements (CNE is consistent with the general trend of high levels of conservation of noncoding DNA in the slowly evolving Latimeria genome.

  5. Phylogenetic analysis of a newfound bat-borne hantavirus supports a laurasiatherian host association for ancestral mammalian hantaviruses.

    Science.gov (United States)

    Witkowski, Peter T; Drexler, Jan F; Kallies, René; Ličková, Martina; Bokorová, Silvia; Mananga, Gael D; Szemes, Tomáš; Leroy, Eric M; Krüger, Detlev H; Drosten, Christian; Klempa, Boris

    2016-07-01

    Until recently, hantaviruses (family Bunyaviridae) were believed to originate from rodent reservoirs. However, genetically distinct hantaviruses were lately found in shrews and moles, as well as in bats from Africa and Asia. Bats (order Chiroptera) are considered important reservoir hosts for emerging human pathogens. Here, we report on the identification of a novel hantavirus, provisionally named Makokou virus (MAKV), in Noack's Roundleaf Bat (Hipposideros ruber) in Gabon, Central Africa. Phylogenetic analysis of the genomic l-segment showed that MAKV was the most closely related to other bat-borne hantaviruses and shared a most recent common ancestor with the Asian hantaviruses Xuan Son and Laibin. Breakdown of the virus load in a bat animal showed that MAKV resembles rodent-borne hantaviruses in its organ distribution in that it predominantly occurred in the spleen and kidney; this provides a first insight into the infection pattern of bat-borne hantaviruses. Ancestral state reconstruction based on a tree of l gene sequences of all relevant hantavirus lineages was combined with phylogenetic fossil host hypothesis testing, leading to a statistically significant rejection of the mammalian superorder Euarchontoglires (including rodents) but not the superorder Laurasiatheria (including shrews, moles, and bats) as potential hosts of ancestral hantaviruses at most basal tree nodes. Our data supports the emerging concept of bats as previously overlooked hantavirus reservoir hosts. PMID:27051047

  6. Study on the Relationship Between the Ploidy Level of Microspore-Derived Plants and the Number of Chloroplast in Stomatal Guard Cells in Brassica oleracea

    Institute of Scientific and Technical Information of China (English)

    YUAN Su-xia; LIU Yu-mei; FANG Zhi-yuan; YANG Li-mei; ZHUANG Mu; ZHANG Yang-yong; SUN Pei-tian

    2009-01-01

    The relationship between the ploidy level of microspore-derived plants and chloroplast number in stomatal guard cells was studied in cabbage, broccoli, and Chinese kale. In the experiment, distribution statistics analysis and t-test were used to perform statistical analysis on chloroplast number of different ploidy level in those stomatal guard cells mentioned above, and morphology identifying and chromosome counting were used to test accuracy of counting chloroplast number in stomatal guard cells. The chloroplast average number in stomatal guard cells was very similar among the different leaf positions on the same plant and among the different locations in the same leaf, while the chloroplast number varied significantly among the different ploidy stoma in the same variety. All the distributions of the chloroplast number in different ploidy stoma were normal distribution fitted. A correlation has been established between ploidy and chloroplast number in the stomatal guard cells. In every single stoma of microspore-derived plants, the chloroplast number for a haploid should not be more than 10, diploids 11 to 15, and polyploids more than 15. The accuracy of this method for identification of different ploidy plants was 93.93%. Furthermore, the accuracy of this method was reliable and did not vary with the plants growth conditions. Therefore, the chromosome ploidy of plants derived from microspore culture in cabbage, broccoli, and Chinese kale can be identified by simply counting the chloroplast number in stomatal guard cells.

  7. The Path to Thioredoxin and Redox Regulation in Chloroplasts.

    Science.gov (United States)

    Buchanan, Bob B

    2016-04-29

    After a brief discussion of my graduate work at Duke University, I describe a series of investigations on redox proteins at the University of California, Berkeley. Starting with ferredoxin from fermentative bacteria, the Berkeley research fostered experiments that uncovered a pathway for fixing CO2 in bacterial photosynthesis. The carbon work, in turn, opened new vistas, including the discovery that thioredoxin functions universally in regulating the Calvin-Benson cycle in oxygenic photosynthesis. These experiments, which took place over a 50-year period, led to the formulation of a set of biological principles and set the stage for research demonstrating a role for redox in the regulation of previously unrecognized processes extending far beyond photosynthesis. PMID:27128465

  8. Role of the chloroplast in the predatory dinoflagellate Karlodinium armiger

    DEFF Research Database (Denmark)

    Berge, Terje; Hansen, Per Juel

    2016-01-01

    manner. Cellular chlorophyll a contents and photosynthetic rates were ~40% and ~70% lower, respectively, in long-term compared to short-term starved phototrophic cells at irradiances of 70-250 µmol photons m-2 s-1. Carbon fixation was important for achieving high mixotrophic growth rates, especially in.......65d-1), suggesting that it relies heavily on phagotrophic nutrition. To explore the reasons for this phenomenon and the role of the plastids for the growth of K. armiger, we measured C14 fixation rates, chlorophyll a content and growth rates as a function of irradiance in short and long term prey...... starved cultures. In starved cultures, rates of photosynthesis were relatively high and increased as a function of irradiance, in spite of the fact that growth rates remained low. In prey fed cultures, both ingestion and growth rates of K. armiger increased as a function of irradiance in a saturating...

  9. PAPP5 is involved in the tetrapyrrole mediated plastid signalling during chloroplast development.

    Directory of Open Access Journals (Sweden)

    Juan de Dios Barajas-López

    Full Text Available The initiation of chloroplast development in the light is dependent on nuclear encoded components. The nuclear genes encoding key components in the photosynthetic machinery are regulated by signals originating in the plastids. These plastid signals play an essential role in the regulation of photosynthesis associated nuclear genes (PhANGs when proplastids develop into chloroplasts. One of the plastid signals is linked to the tetrapyrrole biosynthesis and accumulation of the intermediates the Mg-ProtoIX and its methyl ester Mg-ProtoIX-ME. Phytochrome-Associated Protein Phosphatase 5 (PAPP5 was isolated in a previous study as a putative Mg-ProtoIX interacting protein. In order to elucidate if there is a biological link between PAPP5 and the tetrapyrrole mediated signal we generated double mutants between the Arabidopsis papp5 and the crd mutants. The crd mutant over-accumulates Mg-ProtoIX and Mg-ProtoIX-ME and the tetrapyrrole accumulation triggers retrograde signalling. The crd mutant exhibits repression of PhANG expression, altered chloroplast morphology and a pale phenotype. However, in the papp5crd double mutant, the crd phenotype is restored and papp5crd accumulated wild type levels of chlorophyll, developed proper chloroplasts and showed normal induction of PhANG expression in response to light. Tetrapyrrole feeding experiments showed that PAPP5 is required to respond correctly to accumulation of tetrapyrroles in the cell and that PAPP5 is most likely a component in the plastid signalling pathway down stream of the tetrapyrrole Mg-ProtoIX/Mg-ProtoIX-ME. Inhibition of phosphatase activity phenocopied the papp5crd phenotype in the crd single mutant demonstrating that PAPP5 phosphatase activity is essential to mediate the retrograde signal and to suppress PhANG expression in the crd mutant. Thus, our results suggest that PAPP5 receives an inbalance in the tetrapyrrole biosynthesis through the accumulation of Mg-ProtoIX and acts as a negative

  10. Tic20 forms a channel independent of Tic110 in chloroplasts

    Directory of Open Access Journals (Sweden)

    Benz J Philipp

    2011-09-01

    Full Text Available Abstract Background The Tic complex (Translocon at the inner envelope membrane of chloroplasts mediates the translocation of nuclear encoded chloroplast proteins across the inner envelope membrane. Tic110 forms one prominent protein translocation channel. Additionally, Tic20, another subunit of the complex, was proposed to form a protein import channel - either together with or independent of Tic110. However, no experimental evidence for Tic20 channel activity has been provided so far. Results We performed a comprehensive biochemical and electrophysiological study to characterize Tic20 in more detail and to gain a deeper insight into its potential role in protein import into chloroplasts. Firstly, we compared transcript and protein levels of Tic20 and Tic110 in both Pisum sativum and Arabidopsis thaliana. We found the Tic20 protein to be generally less abundant, which was particularly pronounced in Arabidopsis. Secondly, we demonstrated that Tic20 forms a complex larger than 700 kilodalton in the inner envelope membrane, which is clearly separate from Tic110, migrating as a dimer at about 250 kilodalton. Thirdly, we defined the topology of Tic20 in the inner envelope, and found its N- and C-termini to be oriented towards the stromal side. Finally, we successfully reconstituted overexpressed and purified full-length Tic20 into liposomes. Using these Tic20-proteoliposomes, we could demonstrate for the first time that Tic20 can independently form a cation selective channel in vitro. Conclusions The presented data provide first biochemical evidence to the notion that Tic20 can act as a channel protein within the chloroplast import translocon complex. However, the very low abundance of Tic20 in the inner envelope membranes indicates that it cannot form a major protein translocation channel. Furthermore, the independent complex formation of Tic20 and Tic110 argues against a joint channel formation. Thus, based on the observed channel activity of Tic20

  11. Combined effects of simulated acid rain and lanthanum chloride on chloroplast structure and functional elements in rice.

    Science.gov (United States)

    Hu, Huiqing; Wang, Lihong; Zhou, Qing; Huang, Xiaohua

    2016-05-01

    Acid rain and rare earth element (REE) pollution exist simultaneously in many agricultural regions. However, how REE pollution and acid rain affect plant growth in combination remains largely unknown. In this study, the combined effects of simulated acid rain and lanthanum chloride (LaCl3) on chloroplast morphology, chloroplast ultrastructure, functional element contents, chlorophyll content, and the net photosynthetic rate (P n) in rice (Oryza sativa) were investigated by simulating acid rain and rare earth pollution. Under the combined treatment of simulated acid rain at pH 4.5 and 0.08 mM LaCl3, the chloroplast membrane was smooth, proteins on this membrane were uniform, chloroplast structure was integrated, and the thylakoids were orderly arranged, and simulated acid rain and LaCl3 exhibited a mild antagonistic effect; the Mg, Ca, Mn contents, the chlorophyll content, and the P n increased under this combined treatment, with a synergistic effect of simulated acid rain and LaCl3. Under other combined treatments of simulated acid rain and LaCl3, the chloroplast membrane surface was uneven, a clear "hole" was observed on the surface of chloroplasts, and the thylakoids were dissolved and loose; and the P n and contents of functional elements (P, Mg, K, Ca, Mn, Fe, Ni, Cu, Zn and Mo) and chlorophyll decreased. Under these combined treatments, simulated acid rain and LaCl3 exhibited a synergistic effect. Based on the above results, a model of the combined effects of simulated acid rain and LaCl3 on plant photosynthesis was established in order to reveal the combined effects on plant photosynthesis, especially on the photosynthetic organelle-chloroplast. Our results would provide some references for further understanding the mechanism of the combined effects of simulated acid rain and LaCl3 on plant photosynthesis. PMID:26815371

  12. Modelling C₃ photosynthesis from the chloroplast to the ecosystem.

    Science.gov (United States)

    Bernacchi, Carl J; Bagley, Justin E; Serbin, Shawn P; Ruiz-Vera, Ursula M; Rosenthal, David M; Vanloocke, Andy

    2013-09-01

    Globally, photosynthesis accounts for the largest flux of CO₂ from the atmosphere into ecosystems and is the driving process for terrestrial ecosystem function. The importance of accurate predictions of photosynthesis over a range of plant growth conditions led to the development of a C₃ photosynthesis model by Farquhar, von Caemmerer & Berry that has become increasingly important as society places greater pressures on vegetation. The photosynthesis model has played a major role in defining the path towards scientific understanding of photosynthetic carbon uptake and the role of photosynthesis on regulating the earth's climate and biogeochemical systems. In this review, we summarize the photosynthesis model, including its continued development and applications. We also review the implications these developments have on quantifying photosynthesis at a wide range of spatial and temporal scales, and discuss the model's role in determining photosynthetic responses to changes in environmental conditions. Finally, the review includes a discussion of the larger-scale modelling and remote-sensing applications that rely on the leaf photosynthesis model and are likely to open new scientific avenues to address the increasing challenges to plant productivity over the next century. PMID:23590343

  13. Complete chloroplast genome of Oncidium Gower Ramsey and evaluation of molecular markers for identification and breeding in Oncidiinae

    Directory of Open Access Journals (Sweden)

    Daniell Henry

    2010-04-01

    Full Text Available Abstract Background Oncidium spp. produce commercially important orchid cut flowers. However, they are amenable to intergeneric and inter-specific crossing making phylogenetic identification very difficult. Molecular markers derived from the chloroplast genome can provide useful tools for phylogenetic resolution. Results The complete chloroplast genome of the economically important Oncidium variety Onc. Gower Ramsey (Accession no. GQ324949 was determined using a polymerase chain reaction (PCR and Sanger based ABI sequencing. The length of the Oncidium chloroplast genome is 146,484 bp. Genome structure, gene order and orientation are similar to Phalaenopsis, but differ from typical Poaceae, other monocots for which there are several published chloroplast (cp genome. The Onc. Gower Ramsey chloroplast-encoded NADH dehydrogenase (ndh genes, except ndhE, lack apparent functions. Deletion and other types of mutations were also found in the ndh genes of 15 other economically important Oncidiinae varieties, except ndhE in some species. The positions of some species in the evolution and taxonomy of Oncidiinae are difficult to identify. To identify the relationships between the 15 Oncidiinae hybrids, eight regions of the Onc. Gower Ramsey chloroplast genome were amplified by PCR for phylogenetic analysis. A total of 7042 bp derived from the eight regions could identify the relationships at the species level, which were supported by high bootstrap values. One particular 1846 bp region, derived from two PCR products (trnHGUG -psbA and trnFGAA-ndhJ was adequate for correct phylogenetic placement of 13 of the 15 varieties (with the exception of Degarmoara Flying High and Odontoglossum Violetta von Holm. Thus the chloroplast genome provides a useful molecular marker for species identifications. Conclusion In this report, we used Phalaenopsis. aphrodite as a prototype for primer design to complete the Onc. Gower Ramsey genome sequence. Gene annotation showed

  14. Research Progress of Sugarcane Chloroplast Genome%甘蔗叶绿体基因组研究进展

    Institute of Scientific and Technical Information of China (English)

    吴杨; 周会

    2013-01-01

    Along with the development of modern molecular biology technologies, complete chloroplast genomes have been sequenced in various plant species to date, and the structure, function and expression of these genes have been deter-mined. The chloroplast genome structure in most higher plants is stable, since the gene number, arrangement and composition are conservative. The determination of sugarcane chloroplast genome sequence laid a good foundation for sugarcane chloroplast related research. This article gives a review on the research progress of sugarcane chloroplast genome through the chloroplast genome map, gene structure, function, chloroplast RNA editing, and phylogenetic analysis in Saccharum and relat-ed genera. This study held great potential to clarify more directions in researches, including sugarcane chloroplast genetic transformation, complete chloroplast nu-cleotide sequence determination in Saccharum and closely related genera, cpSSRs development and application.%随着现代分子生物学技术的发展,目前已经完成了多种植物叶绿体基因组的全序列测定,并研究了这些基因的结构、功能与表达。大部分高等植物的叶绿体基因组结构稳定,基因数量、排列顺序及组成上具有保守性。甘蔗叶绿体基因组测序工作的完成为甘蔗叶绿体相关研究奠定了良好基础。文章从甘蔗叶绿体基因组图谱、结构和功能基因、叶绿体RNA编辑以及甘蔗属叶绿体系统进化等方面综合概述了甘蔗叶绿体基因组研究取得的成果,并从甘蔗叶绿体遗传转化、甘蔗及近缘属叶绿体基因组测序和叶绿体基因组 cpSSRs开发利用等方面指出甘蔗叶绿体基因组今后的研究方向。

  15. The complete chloroplast genome sequence of Brachypodium distachyon: sequence comparison and phylogenetic analysis of eight grass plastomes

    Directory of Open Access Journals (Sweden)

    Anderson Olin D

    2008-07-01

    Full Text Available Abstract Background Wheat, barley, and rye, of tribe Triticeae in the Poaceae, are among the most important crops worldwide but they present many challenges to genomics-aided crop improvement. Brachypodium distachyon, a close relative of those cereals has recently emerged as a model for grass functional genomics. Sequencing of the nuclear and organelle genomes of Brachypodium is one of the first steps towards making this species available as a tool for researchers interested in cereals biology. Findings The chloroplast genome of Brachypodium distachyon was sequenced by a combinational approach using BAC end and shotgun sequences derived from a selected BAC containing the entire chloroplast genome. Comparative analysis indicated that the chloroplast genome is conserved in gene number and organization with respect to those of other cereals. However, several Brachypodium genes evolve at a faster rate than those in other grasses. Sequence analysis reveals that rice and wheat have a ~2.1 kb deletion in their plastid genomes and this deletion must have occurred independently in both species. Conclusion We demonstrate that BAC libraries can be used to sequence plastid, and likely other organellar, genomes. As expected, the Brachypodium chloroplast genome is very similar to those of other sequenced grasses. The phylogenetic analyses and the pattern of insertions and deletions in the chloroplast genome confirmed that Brachypodium is a close relative of the tribe Triticeae. Nevertheless, we show that some large indels can arise multiple times and may confound phylogenetic reconstruction.

  16. Clues to the signals for chloroplast photo-relocation from the lifetimes of accumulation and avoidance responses

    Institute of Scientific and Technical Information of China (English)

    Takeshi Higa; Masamitsu Wada

    2015-01-01

    Chloroplast photo-relocation movement is crucial for plant survival;however, the mechanism of this phenome-non is stil poorly understood. Especial y, the signal that goes from photoreceptor to chloroplast is unknown, although the photoreceptors (phototropin 1 and 2) have been identified and an actin structure (chloroplast actin filaments) has been characterized that is specific for chloroplast movement. Here, in gametophytes of the fern Adiantum capillus-veneris, gametophores of the moss Physcomiterella patens, and leaves of the seed plant Arabidopsis thaliana, we sought to characterize the signaling system by measuring the lifetime of the induced response. Chloroplast movements were induced by microbeam irradiation with high-intensity blue light and recorded. The lifetime of the avoidance state was measured as a lag time between switching off the beam and the loss of avoidance behavior, and that of the accumulation state was measured as the duration of accumulation behavior fol owing the extinction of the beam. The lifetime for the avoidance response state is approximately 3–4 min and that for the accumulation response is 19–28 min. These data suggest that the two responses are based on distinct signals.

  17. PBR1 selectively controls biogenesis of photosynthetic complexes by modulating translation of the large chloroplast gene Ycf1 in Arabidopsis.

    Science.gov (United States)

    Yang, Xiao-Fei; Wang, Yu-Ting; Chen, Si-Ting; Li, Ji-Kai; Shen, Hong-Tao; Guo, Fang-Qing

    2016-01-01

    The biogenesis of photosystem I (PSI), cytochrome b 6 f (Cytb 6 f) and NADH dehydrogenase (NDH) complexes relies on the spatially and temporally coordinated expression and translation of both nuclear and chloroplast genes. Here we report the identification of photosystem biogenesis regulator 1 (PBR1), a nuclear-encoded chloroplast RNA-binding protein that regulates the concerted biogenesis of NDH, PSI and Cytb 6 f complexes. We identified Ycf1, one of the two largest chloroplast genome-encoded open reading frames as the direct downstream target protein of PBR1. Biochemical and molecular analyses reveal that PBR1 regulates Ycf1 translation by directly binding to its mRNA. Surprisingly, we further demonstrate that relocation of the chloroplast gene Ycf1 fused with a plastid-transit sequence to the nucleus bypasses the requirement of PBR1 for Ycf1 translation, which sufficiently complements the defects in biogenesis of NDH, PSI and Cytb 6 f complexes in PBR1-deficient plants. Remarkably, the nuclear-encoded PBR1 tightly controls the expression of the chloroplast gene Ycf1 at the translational level, which is sufficient to sustain the coordinated biogenesis of NDH, PSI and Cytb 6 f complexes as a whole. Our findings provide deep insights into better understanding of how a predominant nuclear-encoded factor can act as a migratory mediator and undergoes selective translational regulation of the target plastid gene in controlling biogenesis of photosynthetic complexes. PMID:27462450

  18. Effect of light intensity on pigments and main acyl lipids during 'natural' chloroplast development in wheat seedlings.

    Science.gov (United States)

    Lechowicz, W; Maternicka, K; Faltynowicz, M; Poskuta, J

    1986-01-01

    The content and composition of pigments and acyl lipids (monogalactosyl diacylglycerol, digalactosyl diacylglycerol and phosphatidyl glycerol) have been investigated in developing chloroplasts isolated from successive 2-cm sections along the leaves of wheat seedlings grown either under 100, 30 or 3 W·m(-2). In all examined stages of plastid development chlorophyll a/b and chlorophyll/carotenoid ratios were higher with increasing irradiance, whereas chlorophyll content expressed on fresh weight basis gradually decreased.Concentrations of monogalactosyl diacylglycerol, digalactosyl diacylglycerol and phosphatidyl glycerol decreased per chlorophyll unit with increasing plastid maturity. The higher was the light intensity applied during plant growth, the higher were galactolipid and phosphatidyl glycerol contents in developing chloroplasts. During plastid development the percentage of α-linolenic acid markedly increased in total and individual acyl lipids. Under high light conditions, the accumulation of this fatty acid proceeded more rapidly. Significantly higher proportion of α-linolenic acid was found in acyl lipid fraction of chloroplasts differentiating in high light grown plants, than in those from plants exposed to lower light intensities. The differences in the double bond index may indicate higher fluidity of thylakoid membranes in sun-type chloroplasts.Trans-3Δ-hexadecenoic acid, virtually absent in the youngest plastids, was found in much higher concentration (per chlorophyll unit and as mol % of phosphatidyl glycerol fatty acids) in chloroplasts developing at high light conditions. PMID:24443210

  19. Genetic Analysis of Arabidopsis Mutants Impaired in Plastid Lipid Import Reveals a Role of Membrane Lipids in Chloroplast Division

    Energy Technology Data Exchange (ETDEWEB)

    Fan, J.; Xu, C.

    2011-03-01

    The biogenesis of photosynthetic membranes in plants relies largely on lipid import from the endoplasmic reticulum (ER) and this lipid transport process is mediated by TGD proteins in Arabidopsis. Such a dependency of chloroplast biogenesis on ER-to-plastid lipid transport was recently exemplified by analyzing double mutants between tgd1-1 or tgd4-3 and fad6 mutants. The fad6 mutants are defective in the desaturation of membrane lipids in chloroplasts and therefore dependent on import of polyunsaturated lipid precursors from the ER for constructing a competent thylakoid membrane system. In support of a critical role of TGD proteins in ER-to-plastid lipid trafficking, we showed that the introduction of the tgd mutations into fad6 mutant backgrounds led to drastic reductions in relative amounts of thylakoid lipids. Moreover, the tgd1-1 fad6 and tgd4-3 fad6 double mutants were deficient in polyunsaturated fatty acids in chloroplast membrane lipids, and severely compromised in the biogenesis of photosynthetic membrane systems. Here we report that these double mutants are severely impaired in chloroplast division. The possible role of membrane lipids in chloroplast division is discussed.

  20. The complete chloroplast genome sequence of Pelargonium xhortorum: Or ganization and evolution of the largest and most highlyrearranged chloroplast genome of land plants

    Energy Technology Data Exchange (ETDEWEB)

    Chumley, Timothy W.; Palmer, Jeffrey D.; Mower, Jeffrey P.; Fourcade, H. Matthew; Calie, Patrick J.; Boore, Jeffrey L.; Jansen,Robert K.

    2006-01-20

    The chloroplast genome of Pelargonium e hortorum has beencompletely sequenced. It maps as a circular molecule of 217,942 bp, andis both the largest and most rearranged land plant chloroplast genome yetsequenced. It features two copies of a greatly expanded inverted repeat(IR) of 75,741 bp each, and consequently diminished single copy regionsof 59,710 bp and 6,750 bp. It also contains two different associations ofrepeated elements that contribute about 10 percent to the overall sizeand account for the majority of repeats found in the genome. Theyrepresent hotspots for rearrangements and gene duplications and include alarge number of pseudogenes. We propose simple models that account forthe major rearrangements with a minimum of eight IR boundary changes and12 inversions in addition to a several insertions of duplicated sequence.The major processes at work (duplication, IR expansion, and inversion)have disrupted at least one and possibly two or three transcriptionaloperons, and the genes involved in these disruptions form the core of thetwo major repeat associations. Despite the vast increase in size andcomplexity of the genome, the gene content is similar to that of otherangiosperms, with the exceptions of a large number of pseudogenes as partof the repeat associations, the recognition of two open reading frames(ORF56 and ORF42) in the trnA intron with similarities to previouslyidentified mitochondrial products (ACRS and pvs-trnA), the loss of accDand trnT-GGU, and in particular, the lack of a recognizably functionalrpoA. One or all of three similar open reading frames may possibly encodethe latter, however.

  1. Estimating Divergence Time and Ancestral Effective Population Size of Bornean and Sumatran Orangutan Subspecies Using a Coalescent Hidden Markov Model

    DEFF Research Database (Denmark)

    Mailund, Thomas; Dutheil, Julien; Hobolth, Asger;

    2011-01-01

    ue to genetic variation in the ancestor of two populations or two species, the divergence time for DNA sequences from two populations is variable along the genome. Within genomic segments all bases will share the same divergence—because they share a most recent common ancestor—when no recombination...... event has occurred to split them apart. The size of these segments of constant divergence depends on the recombination rate, but also on the speciation time, the effective population size of the ancestral population, as well as demographic effects and selection. Thus, inference of these parameters may...... be possible if we can decode the divergence times along a genomic alignment. Here, we present a new hidden Markov model that infers the changing divergence (coalescence) times along the genome alignment using a coalescent framework, in order to estimate the speciation time, the recombination rate...

  2. An Interpretation of the Ancestral Codon from Miller’s Amino Acids and Nucleotide Correlations in Modern Coding Sequences

    Science.gov (United States)

    Carels, Nicolas; de Leon, Miguel Ponce

    2015-01-01

    Purine bias, which is usually referred to as an “ancestral codon”, is known to result in short-range correlations between nucleotides in coding sequences, and it is common in all species. We demonstrate that RWY is a more appropriate pattern than the classical RNY, and purine bias (Rrr) is the product of a network of nucleotide compensations induced by functional constraints on the physicochemical properties of proteins. Through deductions from universal correlation properties, we also demonstrate that amino acids from Miller’s spark discharge experiment are compatible with functional primeval proteins at the dawn of living cell radiation on earth. These amino acids match the hydropathy and secondary structures of modern proteins. PMID:25922573

  3. Low pathogenic avian influenza (H9N2) in chicken: Evaluation of an ancestral H9-MVA vaccine.

    Science.gov (United States)

    Ducatez, Mariette F; Becker, Jens; Freudenstein, Astrid; Delverdier, Maxence; Delpont, Mattias; Sutter, Gerd; Guérin, Jean-Luc; Volz, Asisa

    2016-06-30

    Modified Vaccinia Ankara (MVA) has proven its efficacy as a recombinant vector vaccine for numerous pathogens including influenza virus. The present study aimed at evaluating a recombinant MVA candidate vaccine against low pathogenic avian influenza virus subtype H9N2 in the chicken model. As the high genetic and antigenic diversity of H9N2 viruses increases vaccine design complexity, one strategy to widen the range of vaccine coverage is to use an ancestor sequence. We therefore generated a recombinant MVA encoding for the gene sequence of an ancestral hemagglutinin H9 protein (a computationally derived amino acid sequence of the node of the H9N2 G1 lineage strains was obtained using the ANCESCON program). We analyzed the genetics and the growth properties of the MVA vector virus confirming suitability for use under biosafety level 1 and tested its efficacy when applied either as an intra-muscular (IM) or an oral vaccine in specific pathogen free chickens challenged with A/chicken/Tunisia/12/2010(H9N2). Two control groups were studied in parallel (unvaccinated and inoculated birds; unvaccinated and non-inoculated birds). IM vaccinated birds seroconverted as early as four days post vaccination and neutralizing antibodies were detected against A/chicken/Tunisia/12/2010(H9N2) in all the birds before challenge. The role of local mucosal immunity is unclear here as no antibodies were detected in eye drop or aerosol vaccinated birds. Clinical signs were not detected in any of the infected birds even in absence of vaccination. Virus replication was observed in both vaccinated and unvaccinated chickens, suggesting the MVA-ancestral H9 vaccine may not stop virus spread in the field. However vaccinated birds showed less histological damage, fewer influenza-positive cells and shorter virus shedding than their unvaccinated counterparts. PMID:27259828

  4. The impact of ancestral population size and incomplete lineage sorting on Bayesian estimation of species divergence times

    Institute of Scientific and Technical Information of China (English)

    Konstantinos ANGELIS; Mario DOS REIS

    2015-01-01

    Although the effects of the coalescent process on sequence divergence and genealogies are well understood, the vir-tual majority of studies that use molecular sequences to estimate times of divergence among species have failed to account for the coalescent process. Here we study the impact of ancestral population size and incomplete lineage sorting on Bayesian estimates of species divergence times under the molecular clock when the inference model ignores the coalescent process. Using a combi-nation of mathematical analysis, computer simulations and analysis of real data, we find that the errors on estimates of times and the molecular rate can be substantial when ancestral populations are large and when there is substantial incomplete lineage sort-ing. For example, in a simple three-species case, we find that if the most precise fossil calibration is placed on the root of the phylogeny, the age of the internal node is overestimated, while if the most precise calibration is placed on the internal node, then the age of the root is underestimated. In both cases, the molecular rate is overestimated. Using simulations on a phylogeny of nine species, we show that substantial errors in time and rate estimates can be obtained even when dating ancient divergence events. We analyse the hominoid phylogeny and show that estimates of the neutral mutation rate obtained while ignoring the coalescent are too high. Using a coalescent-based technique to obtain geological times of divergence, we obtain estimates of the mutation rate that are within experimental estimates and we also obtain substantially older divergence times within the phylogeny [Current Zoology 61 (5): 874–885, 2015].

  5. PhyloBot: A Web Portal for Automated Phylogenetics, Ancestral Sequence Reconstruction, and Exploration of Mutational Trajectories

    Science.gov (United States)

    Hanson-Smith, Victor; Johnson, Alexander

    2016-01-01

    The method of phylogenetic ancestral sequence reconstruction is a powerful approach for studying evolutionary relationships among protein sequence, structure, and function. In particular, this approach allows investigators to (1) reconstruct and “resurrect” (that is, synthesize in vivo or in vitro) extinct proteins to study how they differ from modern proteins, (2) identify key amino acid changes that, over evolutionary timescales, have altered the function of the protein, and (3) order historical events in the evolution of protein function. Widespread use of this approach has been slow among molecular biologists, in part because the methods require significant computational expertise. Here we present PhyloBot, a web-based software tool that makes ancestral sequence reconstruction easy. Designed for non-experts, it integrates all the necessary software into a single user interface. Additionally, PhyloBot provides interactive tools to explore evolutionary trajectories between ancestors, enabling the rapid generation of hypotheses that can be tested using genetic or biochemical approaches. Early versions of this software were used in previous studies to discover genetic mechanisms underlying the functions of diverse protein families, including V-ATPase ion pumps, DNA-binding transcription regulators, and serine/threonine protein kinases. PhyloBot runs in a web browser, and is available at the following URL: http://www.phylobot.com. The software is implemented in Python using the Django web framework, and runs on elastic cloud computing resources from Amazon Web Services. Users can create and submit jobs on our free server (at the URL listed above), or use our open-source code to launch their own PhyloBot server. PMID:27472806

  6. Stem cell-specific activation of an ancestral myc protooncogene with conserved basic functions in the early metazoan Hydra

    Science.gov (United States)

    Hartl, Markus; Mitterstiller, Anna-Maria; Valovka, Taras; Breuker, Kathrin; Hobmayer, Bert; Bister, Klaus

    2010-01-01

    The c-myc protooncogene encodes a transcription factor (Myc) with oncogenic potential. Myc and its dimerization partner Max are bHLH-Zip DNA binding proteins controlling fundamental cellular processes. Deregulation of c-myc leads to tumorigenesis and is a hallmark of many human cancers. We have identified and extensively characterized ancestral forms of myc and max genes from the early diploblastic cnidarian Hydra, the most primitive metazoan organism employed so far for the structural, functional, and evolutionary analysis of these genes. Hydra myc is specifically activated in all stem cells and nematoblast nests which represent the rapidly proliferating cell types of the interstitial stem cell system and in proliferating gland cells. In terminally differentiated nerve cells, nematocytes, or epithelial cells, myc expression is not detectable by in situ hybridization. Hydra max exhibits a similar expression pattern in interstitial cell clusters. The ancestral Hydra Myc and Max proteins display the principal design of their vertebrate derivatives, with the highest degree of sequence identities confined to the bHLH-Zip domains. Furthermore, the 314-amino acid Hydra Myc protein contains basic forms of the essential Myc boxes I through III. A recombinant Hydra Myc/Max complex binds to the consensus DNA sequence CACGTG with high affinity. Hybrid proteins composed of segments from the retroviral v-Myc oncoprotein and the Hydra Myc protein display oncogenic potential in cell transformation assays. Our results suggest that the principal functions of the Myc master regulator arose very early in metazoan evolution, allowing their dissection in a simple model organism showing regenerative ability but no senescence. PMID:20142507

  7. ¿Con o sin ancestros? Vigencia de lo ancestral en la Amazonía peruana

    Directory of Open Access Journals (Sweden)

    Thomas Mouriès

    2014-07-01

    Full Text Available The existence —or not— of the concept of ancestors in the indigenous Amazon has been the subject of much debate. However, regional leaders do not hesitate to call upon ‘ancestral’ knowledge, customs, or territories in the sense that, from an academic point of view, could appear enigmatic. «Ancestral, but… with or without ancestors?» is the question a confused anthropologist might ask. In this article, I propose to offer elements of a response to this question,based on a case study in Peru. First I analyze how Amazonian indigenous leaders, following international law, have adopted the legal notion of ‘ancestral possession’ of their territory to adapt it to the political sphere. This approach accounts for the recent generalization and uniformization of the term ‘ancestral’, but poses the problem of how it articulates with the indigenous cosmologies that it supposes to reflect. For this reason, I explore in the second section the pertinence of the category of ‘ancestor’ in the indigenous Amazon, briefly drawing upon the academic debate in order to define inwhat way this category takes on meaning. Based on testimony from an experienced Awajún leader, we thus return in the third section more explicitly to the different meanings and planes of reference that unfold when one uses the term ‘ancestral’, showing how Amazonian indigenous people not only adopt external conceptual elements and arguments, but also transform them based on their own cosmological singularities and political perspectives.

  8. PhyloBot: A Web Portal for Automated Phylogenetics, Ancestral Sequence Reconstruction, and Exploration of Mutational Trajectories.

    Science.gov (United States)

    Hanson-Smith, Victor; Johnson, Alexander

    2016-07-01

    The method of phylogenetic ancestral sequence reconstruction is a powerful approach for studying evolutionary relationships among protein sequence, structure, and function. In particular, this approach allows investigators to (1) reconstruct and "resurrect" (that is, synthesize in vivo or in vitro) extinct proteins to study how they differ from modern proteins, (2) identify key amino acid changes that, over evolutionary timescales, have altered the function of the protein, and (3) order historical events in the evolution of protein function. Widespread use of this approach has been slow among molecular biologists, in part because the methods require significant computational expertise. Here we present PhyloBot, a web-based software tool that makes ancestral sequence reconstruction easy. Designed for non-experts, it integrates all the necessary software into a single user interface. Additionally, PhyloBot provides interactive tools to explore evolutionary trajectories between ancestors, enabling the rapid generation of hypotheses that can be tested using genetic or biochemical approaches. Early versions of this software were used in previous studies to discover genetic mechanisms underlying the functions of diverse protein families, including V-ATPase ion pumps, DNA-binding transcription regulators, and serine/threonine protein kinases. PhyloBot runs in a web browser, and is available at the following URL: http://www.phylobot.com. The software is implemented in Python using the Django web framework, and runs on elastic cloud computing resources from Amazon Web Services. Users can create and submit jobs on our free server (at the URL listed above), or use our open-source code to launch their own PhyloBot server. PMID:27472806

  9. Orangutan fish eating, primate aquatic fauna eating, and their implications for the origins of ancestral hominin fish eating.

    Science.gov (United States)

    Russon, Anne E; Compost, Alain; Kuncoro, Purwo; Ferisa, Agnes

    2014-12-01

    This paper presents new evidence of fish eating in rehabilitant orangutans living on two Bornean islands and explores its contributions to understanding nonhuman primates' aquatic fauna eating and the origins of ancestral hominin fish eating. We assessed the prevalence of orangutans' fish eating, their techniques for obtaining fish, and possible contributors (ecology, individual differences, humans). We identified 61 events in which orangutans tried to obtain fish, including 19 in which they ate fish. All the orangutans were juvenile-adolescent; all the fish were disabled catfish; and most were obtained and eaten in drier seasons in or near shallow, slow-moving water. Orangutans used several techniques to obtain fish (inadvertent, opportunistic and deliberate hand-catch, scrounge, tool-assisted catch) and probably learned them in that order. Probable contributing factors were orangutan traits (age, pre-existing water or tool skills), island features (social density, water accessibility), and local human fishing. Our review of primates' aquatic fauna eating showed orangutans to be one of 20 species that eat aquatic fauna, one of nine confirmed to eat fish, and one of three that use tools to obtain fish. Primate fish eating is also site-specific within species, partly as a function of habitat (e.g., marine-freshwater, seasonality) and human influence (possibly fostered eating fish or other aquatic fauna at most sites, clearly induced it at some). At tropical freshwater sites, fish eating occurred most often in drier seasons around shallow water. Orangutan and primate findings are generally consistent with Stewart's (2010) reconstruction of the origins of ancestral hominin fish eating, but suggest that it, and tool-assisted fish catching, were possible much earlier. PMID:25038033

  10. Cis-by-Trans regulatory divergence causes the asymmetric lethal effects of an ancestral hybrid incompatibility gene.

    Directory of Open Access Journals (Sweden)

    Shamoni Maheshwari

    Full Text Available The Dobzhansky and Muller (D-M model explains the evolution of hybrid incompatibility (HI through the interaction between lineage-specific derived alleles at two or more loci. In agreement with the expectation that HI results from functional divergence, many protein-coding genes that contribute to incompatibilities between species show signatures of adaptive evolution, including Lhr, which encodes a heterochromatin protein whose amino acid sequence has diverged extensively between Drosophila melanogaster and D. simulans by natural selection. The lethality of D. melanogaster/D. simulans F1 hybrid sons is rescued by removing D. simulans Lhr, but not D. melanogaster Lhr, suggesting that the lethal effect results from adaptive evolution in the D. simulans lineage. It has been proposed that adaptive protein divergence in Lhr reflects antagonistic coevolution with species-specific heterochromatin sequences and that defects in LHR protein localization cause hybrid lethality. Here we present surprising results that are inconsistent with this coding-sequence-based model. Using Lhr transgenes expressed under native conditions, we find no evidence that LHR localization differs between D. melanogaster and D. simulans, nor do we find evidence that it mislocalizes in their interspecific hybrids. Rather, we demonstrate that Lhr orthologs are differentially expressed in the hybrid background, with the levels of D. simulans Lhr double that of D. melanogaster Lhr. We further show that this asymmetric expression is caused by cis-by-trans regulatory divergence of Lhr. Therefore, the non-equivalent hybrid lethal effects of Lhr orthologs can be explained by asymmetric expression of a molecular function that is shared by both orthologs and thus was presumably inherited from the ancestral allele of Lhr. We present a model whereby hybrid lethality occurs by the interaction between evolutionarily ancestral and derived alleles.

  11. Abiotic stresses affect differently the intron splicing and expression of chloroplast genes in coffee plants (Coffea arabica) and rice (Oryza sativa).

    Science.gov (United States)

    Nguyen Dinh, Sy; Sai, Than Zaw Tun; Nawaz, Ghazala; Lee, Kwanuk; Kang, Hunseung

    2016-08-20

    Despite the increasing understanding of the regulation of chloroplast gene expression in plants, the importance of intron splicing and processing of chloroplast RNA transcripts under stress conditions is largely unknown. Here, to understand how abiotic stresses affect the intron splicing and expression patterns of chloroplast genes in dicots and monocots, we carried out a comprehensive analysis of the intron splicing and expression patterns of chloroplast genes in the coffee plant (Coffea arabica) as a dicot and rice (Oryza sativa) as a monocot under abiotic stresses, including drought, cold, or combined drought and heat stresses. The photosynthetic activity of both coffee plants and rice seedlings was significantly reduced under all stress conditions tested. Analysis of the transcript levels of chloroplast genes revealed that the splicing of tRNAs and mRNAs in coffee plants and rice seedlings were significantly affected by abiotic stresses. Notably, abiotic stresses affected differently the splicing of chloroplast tRNAs and mRNAs in coffee plants and rice seedlings. The transcript levels of most chloroplast genes were markedly downregulated in both coffee plants and rice seedlings upon stress treatment. Taken together, these results suggest that coffee and rice plants respond to abiotic stresses via regulating the intron splicing and expression of different sets of chloroplast genes. PMID:27448724

  12. Three-Dimensional Visualization of the Tubular-Lamellar Transformation of the Internal Plastid Membrane Network during Runner Bean Chloroplast Biogenesis.

    Science.gov (United States)

    Kowalewska, Łucja; Mazur, Radosław; Suski, Szymon; Garstka, Maciej; Mostowska, Agnieszka

    2016-04-01

    Chloroplast biogenesis is a complex process that is integrated with plant development, leading to fully differentiated and functionally mature plastids. In this work, we used electron tomography and confocal microscopy to reconstruct the process of structural membrane transformation during the etioplast-to-chloroplast transition in runner bean (Phaseolus coccineus). During chloroplast development, the regular tubular network of paracrystalline prolamellar bodies (PLBs) and the flattened porous membranes of prothylakoids develop into the chloroplast thylakoids. Three-dimensional reconstruction is required to provide us with a more complete understanding of this transformation. We provide spatial models of the bean chloroplast biogenesis that allow such reconstruction of the internal membranes of the developing chloroplast and visualize the transformation from the tubular arrangement to the linear system of parallel lamellae. We prove that the tubular structure of the PLB transforms directly to flat slats, without dispersion to vesicles. We demonstrate that the grana/stroma thylakoid connections have a helical character starting from the early stages of appressed membrane formation. Moreover, we point out the importance of particular chlorophyll-protein complex components in the membrane stacking during the biogenesis. The main stages of chloroplast internal membrane biogenesis are presented in a movie that shows the time development of the chloroplast biogenesis as a dynamic model of this process. PMID:27002023

  13. Loss of matK RNA editing in seed plant chloroplasts

    Directory of Open Access Journals (Sweden)

    Maier Uwe G

    2009-08-01

    Full Text Available Abstract Background RNA editing in chloroplasts of angiosperms proceeds by C-to-U conversions at specific sites. Nuclear-encoded factors are required for the recognition of cis-elements located immediately upstream of editing sites. The ensemble of editing sites in a chloroplast genome differs widely between species, and editing sites are thought to evolve rapidly. However, large-scale analyses of the evolution of individual editing sites have not yet been undertaken. Results Here, we analyzed the evolution of two chloroplast editing sites, matK-2 and matK-3, for which DNA sequences from thousands of angiosperm species are available. Both sites are found in most major taxa, including deep-branching families such as the nymphaeaceae. However, 36 isolated taxa scattered across the entire tree lack a C at one of the two matK editing sites. Tests of several exemplary species from this in silico analysis of matK processing unexpectedly revealed that one of the two sites remain unedited in almost half of all species examined. A comparison of sequences between editors and non-editors showed that specific nucleotides co-evolve with the C at the matK editing sites, suggesting that these nucleotides are critical for editing-site recognition. Conclusion (i Both matK editing sites were present in the common ancestor of all angiosperms and have been independently lost multiple times during angiosperm evolution. (ii The editing activities corresponding to matK-2 and matK-3 are unstable. (iii A small number of third-codon positions in the vicinity of editing sites are selectively constrained independent of the presence of the editing site, most likely because of interacting RNA-binding proteins.

  14. Chloroplasts Are Central Players in Sugar-Induced Leaf Growth1[OPEN

    Science.gov (United States)

    De Milde, Liesbeth; Maleux, Katrien

    2016-01-01

    Leaves are the plant’s powerhouses, providing energy for all organs through sugar production during photosynthesis. However, sugars serve not only as a metabolic energy source for sink tissues but also as signaling molecules, affecting gene expression through conserved signaling pathways to regulate plant growth and development. Here, we describe an in vitro experimental assay, allowing one to alter the sucrose (Suc) availability during early Arabidopsis (Arabidopsis thaliana) leaf development, with the aim to identify the affected cellular and molecular processes. The transfer of seedlings to Suc-containing medium showed a profound effect on leaf growth by stimulating cell proliferation and postponing the transition to cell expansion. Furthermore, rapidly after transfer to Suc, mesophyll cells contained fewer and smaller plastids, which are irregular in shape and contain fewer starch granules compared with control mesophyll cells. Short-term transcriptional responses after transfer to Suc revealed the repression of well-known sugar-responsive genes and multiple genes encoded by the plastid, on the one hand, and up-regulation of a GLUCOSE-6-PHOSPHATE TRANSPORTER (GPT2), on the other hand. Mutant gpt2 seedlings showed no stimulation of cell proliferation and no repression of chloroplast-encoded transcripts when transferred to Suc, suggesting that GPT2 plays a critical role in the Suc-mediated effects on early leaf growth. Our findings, therefore, suggest that induction of GPT2 expression by Suc increases the import of glucose-6-phosphate into the plastids that would repress chloroplast-encoded transcripts, restricting chloroplast differentiation. Retrograde signaling from the plastids would then delay the transition to cell expansion and stimulate cell proliferation. PMID:26932234

  15. Cloning and characterization of two novel chloroplastic glycerol-3-phosphate dehydrogenases from Dunaliella viridis.

    Science.gov (United States)

    He, Yunxia; Meng, Xiangzong; Fan, Qianlan; Sun, Xiaoliang; Xu, Zhengkai; Song, Rentao

    2009-09-01

    Dunaliella, a unicellular green alga, has the unusual ability to survive dramatic osmotic stress by accumulating high concentrations of intracellular glycerol as a compatible solute. The chloroplastic glycerol-3-phosphate dehydrogenase (GPDH) has been considered to be the key enzyme that produces glycerol for osmoregulation in Dunaliella. In this study, we cloned the two most prominent GPDH cDNAs (DvGPDH1 and DvGPDH2) from Dunaliella viridis, which encode two polypeptides of 695 and 701 amino acids, respectively. Unlike higher plant GPDHs, both proteins contained extra phosphoserine phosphatase (SerB) domains at their N-termini in addition to C-terminal GPDH domains. Such bi-domain GPDHs represent a novel type of GPDH and are found exclusively in the chlorophyte lineage. Transient expression of EGFP fusion proteins in tobacco leaf cells demonstrated that both DvGPDH1 and DvGPDH2 are localized in the chloroplast. Overexpression of DvGPDH1 or DvGPDH2 could complement a yeast GPDH mutant (gpd1Delta), but not a yeast SerB mutant (ser2Delta). In vitro assays with purified DvGPDH1 and DvGPDH2 also showed apparent GPDH activity for both, but no SerB activity was detected. Surprisingly, unlike chloroplastic GPDHs from plants, DvGPDH1 and DvGPDH2 could utilize both NADH and NADPH as coenzymes and exhibited significantly higher GPDH activities when NADH was used as the coenzyme. Q-PCR analysis revealed that both genes exhibited transient transcriptional induction of gene expression upon hypersalinity shock, followed by a negative feedback of gene expression. These results shed light on the regulation of glycerol synthesis during salt stress in Dunaliella. PMID:19551475

  16. Viral and chloroplastic signals essential for initiation and efficiency of translation in Agrobacterium tumefaciens.

    Science.gov (United States)

    Ahmad, Tauqeer; Venkataraman, Srividhya; Hefferon, Kathleen; AbouHaidar, Mounir G

    2014-09-12

    The construction of high-level protein expression vectors using the CaMV 35S promoter in concert with highly efficient translation initiation signals for Agrobacterium tumefaciens is a relatively less explored field compared to that of Escherichia coli. In the current study, we experimentally investigated the capacity of the CaMV 35S promoter to direct GFP gene expression in A. tumefaciens in the context of different viral and chloroplastic translation initiation signals. GFP expression and concomitant translational efficiency was monitored by confocal microscopy and Western blot analysis. Among all of the constructs, the highest level of translation was observed for the construct containing the phage T7 translation initiation region followed by the chloroplastic Rubisco Large Subunit (rbcL) 58-nucleotide 5' leader region including its SD-like sequence (GGGAGGG). Replacing the SD-like (GGGAGGG) with non SD-like (TTTATTT) or replacing the remaining 52 nucleotides of rbcL with nonspecific sequence completely abolished translation. In addition, this 58 nucleotide region of rbcL serves as a translational enhancer in plants when located within the 5' UTR of mRNA corresponding to GFP. Other constructs, including those containing sequences upstream of the coat proteins of Alfalfa Mosaic Virus, or the GAGG sequence of T4 phage or the chloroplastic atpI and/or PsbA 5' UTR sequence, supported low levels of GFP expression or none at all. From these studies, we propose that we have created high expression vectors in A. tumefaciens and/or plants which contain the CaMV 35S promoter, followed by the translationally strong T7 SD plus RBS translation initiation region or the rbcL 58-nucleotide 5' leader region upstream of the gene of interest. PMID:25117444

  17. Arabidopsis VARIEGATED 3 encodes a chloroplasttargeted, zinc-finger protein required for chloroplast and palisade cell development

    DEFF Research Database (Denmark)

    Næsted, Henrik; Holm, A.; Jenkins, T.; Nielsen, H.B.; Harris, C.A.; Beale, M.H.; Andersen, M.; Mant, A.; Scheller, H.; Camara, B.; Mattsson, O.; Mundy, J.

    2004-01-01

    The stable, recessive Arabidopsis variegated 3 (var3) mutant exhibits a variegated phenotype due to somatic areas lacking or containing developmentally retarded chloroplasts and greatly reduced numbers of palisade cells. The VAR3 gene, isolated by transposon tagging, encodes the 85.9 kDa VAR3 pro...... pigment profiles are qualitatively similar in wild type and var3, although var3 accumulates lower levels of chlorophylls and carotenoids. These results indicate that VAR3 is a part of a protein complex required for normal chloroplast and palisade cell development....... protein containing novel repeats and zinc fingers described as protein interaction domains. VAR3 interacts specifically in yeast and in vitro with NCED4, a putative polyene chain or carotenoid dioxygenase, and both VAR3 and NCED4 accumulate in the chloroplast stroma. Metabolic profiling demonstrates that...

  18. The complete chloroplast genome sequence of the medicinal plant Glehnia littoralis F.Schmidt ex Miq. (Apiaceae).

    Science.gov (United States)

    Lee, Sang-Choon; Oh Lee, Hyun; Kim, Kyunghee; Kim, Soonok; Yang, Tae-Jin

    2016-09-01

    Glehnia littoralis F. Schmidt ex Miq is an oriental medicinal herb belonging to Apiaceae family, and its dried roots and rhizomes are known to show various pharmacological effects. The complete chlorplast genome of G. littoralis was generated by de novo assembly using whole genome sequencing data. The chloroplast genome of G. littoralis was 147 467 bp in length and divided into four distinct regions: large single copy region (93 493 bp), small single copy region (17 546 bp) and a pair of inverted repeat regions (18 214 bp). A total of 114 genes including 80 protein-coding genes, 30 tRNA genes and 4 rRNA genes were predicted and accounted for 57.1% of the chloroplast genome. Phylogenetic analysis with the reported chloroplast genomes revealed that G. littoralis is an herbal species closely related to Ledebouriella seseloides, an herbal medicinal plant. PMID:26367483

  19. [Changes in the biochemical composition, structure, and function of pea leaf chloroplasts in iron deficiency and root anoxia].

    Science.gov (United States)

    Ladygin, V G

    2004-01-01

    A combined effect of iron deficiency and root anoxia on the biochemical composition, function, and structure of pea leaf chloroplasts was studied. It was found that the chlorosis of apical leaves in response to iron deficiency was determined by the reduction of light-harvesting complexes I and II. Under root anoxia, complexes of the reaction centers of photosystems I and II degraded first. Weak activity was preserved even in yellow and white leaves under the effect of both factors. The ultrastructure of leaf chloroplasts gradually degraded. Initially, intergranal thylakoid sites were reduced, and the longitudinal orientation of grana was disturbed. However, yellow and white leaves still retained small thylakoids and grana. It is concluded that the degrading effects of iron deficiency and root anoxia on the complex composition and leaf chloroplast structure and function are additive because of their autonomous mechanisms. PMID:15553792

  20. A novel phycocyanin-Chla/c2-protein complex isolated from chloroplasts of Chroomonas placoidea

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Nine pigment-protein complexes were separated and characterized from intact Chroomonasplacoidea chloroplasts by IEF. The bands Ⅰ-Ⅵ with their isoelectric points (pI) values from 4 to 6 were phycocyanin components; bands Ⅷ and Ⅸ (pI = 2.8-3.6)were chlorophyll-protein complexes. According to absorption and fluorescence spectra, band Ⅶ was designated as a novel phycocyanin-Chla/c2-protein complex (pI ≈ 3.4-3.7). These results indicated that phycocyanin is structurally and functionally coupled with chlorophyll-protein complex in C. placoidea, and probably interacted with electrostatic force in combination.